[iOS] Auto Resize chrome icons on iOS to make it more consistent with other platforms

[PureWeen]

Description

• Add Telemetry notification if images are being resized so users can address
• By default we will resize images down and then add a flag via AppContext to revert to old behavior and just use the default image

TabbedPage, FlyoutPage, Shell

• Resize the Tab Icons to match the iOS standard icon sizes by default
• Resize the Hamburger Icon by default to the standard icon size for the iOS Toolbar

Opt out

• Use the AppContext API to set a flag where user can disable this behavior if they want.
  • PossibleNames: "iOSResizeTabIconsToSystemDefault", "iOSResizeFlyoutIconToSystemDefault"