Provide support to customize the spacing between header items in Tab View

[naveenkumar-sanjeevirayan]

Root Cause of the Issue

Need to customize the spacing between header items in the TabView. This spacing is currently hardcoded to 36 (see https://github.com/syncfusion/maui-toolkit/blob/main/maui/src/TabView/Control/SfTabBar.cs#L33).

Description of Change

Introduces a new HeaderItemSpacing property on SfTabView, piped down to SfTabBar.

Preserves the current value of 36 as the default.

Screenshots

[Copilot]

Pull request overview

This PR adds support for customizing the spacing between header items in SfTabView. Previously, this spacing was hardcoded to 36 pixels. The change introduces a new HeaderItemSpacing property that can be configured while maintaining backward compatibility by keeping 36 as the default value.

Key Changes:

• Added HeaderItemSpacing bindable property to SfTabView and SfTabBar
• Removed hardcoded _defaultTextPadding field and replaced all usages with the new property
• Added comprehensive unit tests for the new property

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
maui/src/TabView/Control/SfTabView.cs	Added public HeaderItemSpacing property with bindable property declaration, property changed handler, and update method
maui/src/TabView/Control/SfTabBar.cs	Added internal HeaderItemSpacing property, removed hardcoded field, replaced all usages in width calculation methods
maui/tests/Syncfusion.Maui.Toolkit.UnitTest/Navigation/SfTabViewUnitTests.cs	Removed obsolete private field tests, added comprehensive tests for HeaderItemSpacing including default value, set/get, and property changed propagation

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.