[Handlers] Add IndicatorView handler for iOS and Android

[rmarinho]

Description of Change

Adding handler

Implements #

Additions made

public interface IIndicatorView : IView
{
	int Count { get; }
	int Position { get; }
	double IndicatorSize { get; }
	int MaximumVisible { get; }
	bool HideSingle { get; }
	Paint IndicatorsColor { get; }
	Paint PositionIndicatorColor { get; }
	IShape IndicatorShape { get; }
}

public interface ITemplatedIndicatorView : IIndicatorView
{
	ILayout? IndicatorsLayoutOverride { get; }
}

Android	iOS

PR Checklist

• Targets the correct branch
• Tests are passing (or failures are unrelated)
• Targets a single property for a single control (or intertwined few properties)
• Adds the property to the appropriate interface
• Avoids any changes not essential to the handler property
• Adds the mapping to the PropertyMapper in the handler
• Adds the mapping method to the Android, iOS, and Standard aspects of the handler
• Implements the actual property updates (usually in extension methods in the Platform section of Core)
• Tags ported renderer methods with [PortHandler]
• Adds an example of the property to the sample project (MainPage)
• Adds the property to the stub class
• Implements basic property tests in DeviceTests

Does this PR touch anything that might affect accessibility?

• Does this PR introduce a new control? (If yes, add an example using SemanticProperties to the SemanticsPage)
• APIs that modify focusability?
• APIs that modify any text property on a control?
• Does this PR modify view nesting or view arrangement in anyway?
• Is there the smallest possibility that your PR will change accessibility?
• I'm not sure, please help me

If any of the above checkboxes apply to your PR, then the PR will need to provide testing to demonstrate that accessibility still works.

[rmarinho]

Adding default colors

[rmarinho]

CarouselVIew crashes if Loop =true on Android, and doesn't show when Loop=False

[jsuarezruiz]

@rmarinho Is ready to review?, could you rebase to fix the conflicts?. Thnx!

[rmarinho]

@jsuarezruiz yes ready for review

[jsuarezruiz]

Could we include some Device test?. By adding a basic one where an IndicatorView is created with some elements and validating the colors (from each element and from the selected one), it is a great test that allows us to detect if at any time there is a problem setting the size, instantiating or rendering the control as well as assign colors.