Maui SearchBar changes

[edgarfgp]

• Adds the new Properties
• Removes NamedSize from the font modifier as it is deprecated and will be deleted in NET 7 . See https://github.com/dotnet/maui/pull/5088

[TimLariviere]

I'm noticing we let people set the cursor position and selection length but they can't listen for the user changing the cursor or the selection. This is a problem since Fabulous will override whatever the user is doing on each update.

Would be nice to make those modifiers both setter and event listener like the text/textChanged modifier.

static member inline cursorPosition(position: int, onPositionChanged: int -> 'msg)

This is true for Entry, Editor and SearchBar. It's also true for Fabulous.XamarinForms (I even think CursorPosition and SelectionLength are missing in Fabulous.XF for Editor and SearchBar)