Fixed the Header and Footer-Name textbox is cut off in collection view

[NanthiniMahalingam]

Issue Details:

• When dynamically changing the CollectionView's width, the end portion of the CollectionView header's and footer's children gets cut off.
• This issue has been raised in CollectionView1 alone.

Root Cause

• The HeaderView frame update scenario is not considered when the CollectionView size changes.
• ⁠The FooterView frame updates only for a CollectionView with an ItemSource; it does not update when the CollectionView does not contain any items.

Description of Change

• Considered the HeaderView frame update when the CollectionView size changes.
• Updated the FooterView frame where the CollectionView does not contain items, applicable to both horizontal and vertical layouts.

Issues Fixed

Fixes #26186

Validated the behaviour in the following platforms

• Android
• Windows
• iOS
• Mac

Output

iOS platform

Before	After
Before_iOS.mov	After_iOS.mov

macOS platform

Before	After
Before_macOS.mov	After_macOS.mov

[dotnet-policy-service]

Hey there @NanthiniMahalingam! Thank you so much for your PR! Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[rmarinho]

/azp run

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