Expose the ability to have wildcard support for the filtering functionality of the MultiSelect

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

The ASP.NET Core tag helper for the MultiSelect control does not accept the MultiSelectTagMode enum for the tag-mode property (says the type should be a string).

### 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]