Shell SearchHandler icon colors and sizes

Description

1. Cannot set Color of SearchHandler's Magnifier Icon and Left Arrow Icon when SearchBoxVisibility="Collapsible". This Icons is always white. So when I set Background Color to light gray, these icons became almost invisible.
2. Cannot set Size of QueryIcon and Cancelcon inside SearchHandler's input field. I'm trying to use FontImageSource with fontawesome, instead of png image when I can control gaps.
3. Also it would be great to control appearance of input field, including corner radius and shadow.

Thank you!

Public API Changes

SearchHandler.IconColor = Colors.Black;
--or--
Shell.ForegroundColor to affect SearchHandler's icons color.

SearchHandler.QueryIconWidth = 10;
SearchHandler.QueryIconHeight = 10;
--or even better--
SearchHandler.QueryIconView = new ContentView { ... };

SearchHandler.CancelIconWidth = 10;
SearchHandler.CancelIconHeight = 10;
--or even better--
SearchHandler.CancelconView = new ContentView { ... };

SearchHandler.EntryBorderRadius = 10;
SearchHandler.EntryShadow = ...;

Intended Use-Case

Please see an attached screenshot.

Start by locating the Shell SearchHandler entry point and reviewing how its icons and input field are currently configured. The requested work covers icon colors, query and cancel icon sizing or replacement views, and input-field corner radius and shadow; it is done when these appearance options can be controlled for the collapsible SearchHandler.