Implement an AllowCustom option in the MultiSelect, which would make possible to select a custom value that is not present in the data.

This option is available in the Kendo UI for Angular MultiSelect:
https://www.telerik.com/kendo-angular-ui/components/dropdowns/api/multiselectcomponent#allowcustom
https://www.telerik.com/kendo-angular-ui/components/dropdowns/multiselect/custom-values

### Bug report

When using the @Html.EditorFor(m => m) configuration to initialize a MultiSelect TagHelper editor, and passing a specified value for its "id" attribute, the "name" attribute of the <select> element contains a prefix.

### Reproduction of the problem

1. Set the MultiSelect TagHelper as an editor editor of a specified Model property and set the "id" attribute using ViewData:

//Model
[UIHint("CustomMultiSelect")]
public IEnumerable<string> Names { get; set; }

//~.Views/Shared/EditorTemplates/CustomMultiSelect.cshtml
@model IEnumerable<string>
@{
    var id = ViewData["id"]?.ToString();
}
<kendo-multiselect for="@Model" placeholder="some custom behavior" bind-to='ViewData["Data"] as List<string>' id='@id'></kendo-multiselect>

2. Define @Html.EditorFor(a=>a.Names, new{id="customId"}) in a form:

@model MyModel

<form id="myForm" data-method="POST"  asp-action="Save" asp-controller="Home"  class="k-form k-form-md">
    <div class="k-form-layout k-d-grid">
        <div class="k-form-field">
            @Html.EditorFor(a=>a.Names, new{id="customId"})
        </div>
    </div>
    ...
</form>

3. When the MultiSelect is loaded, its "name" attribute is "Names.Names" rather than "Names":

When using the HtmlHelper version of the MultiSelect, the "name" attribute is correct:

//~.Views/Shared/EditorTemplates/CustomMultiSelect.cshtml
@model IEnumerable<string>
@{
    var id = ViewData["id"]?.ToString();
}
@(Html.Kendo().MultiSelectFor(m => m)
  .Placeholder("some custom behavior")
  .BindTo((List<string>)ViewData["Data"])
  .HtmlAttributes(new { id = @id })
)

### Expected/desired behavior

When using the @Html.EditorFor(m => m) configuration, the "name" attribute of the MultiSelect TagHelper must match the Model property name when the "id" attribute is set to a custom value.

### Environment

* **Telerik UI for ASP.NET Core version: 2024.3.806
* **Browser: [all]

### Bug report

The options of the MultiSelect are not serialized when used in Template component.

### Reproduction of the problem

1. Open the following REPL sample: https://netcorerepl.telerik.com/mIOgYfFU47fvuM5N17

2. Review the MultiSelect that is initialized into the Grid's toolbar and notice that its options are not serialized.

### Current behavior

The Template component does not serialize the options of the MultiSelect.

### Expected/desired behavior

The Template component must serialize all options for the MultiSelect.

### Environment

* **Telerik UI for ASP.NET Core version: 2024.2.514
* **Browser: [all]

I'd like to utilize the MultiSelect's Columns as they are available in Kendo UI for jQuery.

Here is the Dojo I am referring to: https://dojo.telerik.com/@martin.tabakov@progress.com/avAvIPEM

Describe the bug
The selected items of the MultiSelect in the Bootstrap Urban theme have invisible text

To reproduce

1. Open this Demo
2. Select any item

Expected behavior
The selected item should have its text visible

Screenshots

**Affected package **

• theme-bootstrap

**Affected suites **

• Kendo UI for jQuery
• Telerik UI for Blazor

Affected browsers

• All

### Bug report

The MultiSelect TagHelper is rendered as a DropDownList and does not allow multiple selections.

### Reproduction of the problem

https://demos.telerik.com/aspnet-core/multiselect/tag-helper

### Expected/desired behavior

The MultiSelect TagHelper should allow multiple selections.

### Environment

* **Kendo UI version: 2021.3.914
* **jQuery version: 1.12.4
* **Browser: [all]

Bug report

MultiSelect configured for server-filtering="true" sends an empty request on focusout

     <kendo-multiselect for="SelectedOrderIds" style="width:100%"
                       placeholder="Select addresses..."
                       datatextfield="ShipName"
                       datavaluefield="OrderID"
                       filter="FilterType.Contains"
                       value="Model.SelectedOrders.Select(x=>x.OrderID)">
        <datasource type="DataSourceTagHelperType.Ajax" server-filtering="true">
            <transport>
                <read url="@Url.Page("Index", "Read")" data="forgeryToken" />
            </transport>
            <schema data="Data">
                <model id="OrderID">
                    <fields>
                        <field name="ShipName" type="string"></field>
                    </fields>
                </model>              
            </schema>
        </datasource>
    </kendo-multiselect>

Reproduction of the problem

TelerikAspNetCoreApp197.zip

1. Run the attached application
2. Enter 34, for example, and select the returned item
3. Click outside of the MultiSelect

Current behavior

An empty request is sent, fetching all data.

Expected/desired behavior

A request should not be sent.

Environment

• Kendo UI version: 2021.1.330
• Browser: [all]

Bug report

Reproduction of the problem

TelerikAspNetCoreApp98.zip

1. Run the attached project.
2. Focus the MultiSelect and type in "bu". The data is filtered and items matching the filter are displayed in the list.
3. Select the first item in the list
4. Type in "bu" again. The list shows the first "bu" item as selected (expected)
5. Scroll down the list, so that another page of the data is loaded
6. Now scroll up to the first item

Current behavior

The item is no longer highlighted as selected.

Expected/desired behavior

The item is highlighted as selected.

Environment

• Kendo UI version: 2020.2.513
• jQuery version: x.y
• Browser: [all]