Updated SafeAreaDemos sample with detailed SafeAreaEdges examples

[Dhivya-SF4094]

Changes

Updated the following example pages with comprehensive documentation:

• Example1EdgeToEdge.xaml - SafeAreaEdges="None"
• Example2RespectAll.xaml - SafeAreaEdges="All"
• Example3KeyboardAware.xaml - SafeAreaEdges="SoftInput"
• Example4Default.xaml - SafeAreaEdges="Default"
• Example5Container.xaml - SafeAreaEdges="Container"

Each example now includes:

• Clear behavior descriptions explaining how content interacts with system UI elements
• Practical use cases demonstrating when to use each SafeAreaEdges value
• Important notes highlighting platform-specific considerations

Related to #712 - Updates SafeAreaDemos sample with detailed documentation for all SafeAreaEdges regions.

Screenshots

SafeAreaEdges	Android	iOS
None
All
SoftInput
Default
Container