When creating an expression that has a decimal, if it doesn't have a zero in front of the decimal, it doesn't evaluate the expression: eg: 0.02 is valid , .02 is invalid
Respect DisplayNameAttribute of the added fields from fields list in ExpressionTextBox.
Currently, the RadExpressionEditor control shows a wavy underline and a red color to indicate that an error is present.
We could introduce API to modify this behavior, which will ultimately be used by the ChangeUnderlineDecoration and ChangeUnderlinesColor methods of the internal RadRichTextBox control.