DOCS: Update InputSystemUIInputModule documentation

[jfreire-unity]

Description

This PR updates Gamepad documentation based on Unity Package API Quality Standards by addressing Score Explanation issues:

• Fix for excessive summary length on xrTrackingOrigin
• Fix for having related links for cancel, leftClick, middleClick, move, moveRepeatDelay, moveRepeatRate, point, rightClick, scrollWheel, submit, trackedDeviceOrientation, trackedDevicePosition.
• Fix for insufficient remarks length on UnassignActions()
• Fix for no summary each for actionsAsset, repeatDelay, repeatRate, trackedDeviceSelect
• Fix for no related links on InputSystemUIInputModule
• Fux for no code samples each for ActivateModule(), AssignDefaultActions(), GetLastRaycastResult(int), IsPointerOverGameObject(int), Process(), UnassignActions()
• Fix for no remarks each for ActivateModule(), AssignDefaultActions(), Awake(), OnDestroy(), OnDisable(), OnEnable(), Process()
• Fix for no summary each for AssignDefaultActions(), Awake(), OnDestroy(), OnDisable(), OnEnable(), Process()
• Fix for no code samples on InputSystemUIInputModule

Testing status & QA

Check if you're happy with my documentation comments.

Overall Product Risks

Please rate the potential complexity and halo effect from low to high for the reviewers. Note down potential risks to specific Editor branches if any.

• Complexity: Minimal
• Halo Effect: Minimal

Comments to reviewers

Only the examples that are reused across the class are in an "external" file so that they can be referenced in multiple examples. I'd like to be consistent about this and have all examples in files. But this is a much bigger effort at the moment, since we're out of docs and I'd like to focus more on the open issues.

Checklist

Before review:

• Changelog entry added.
  • Explains the change in Changed, Fixed, Added sections.
  • For API change contains an example snippet and/or migration example.
  • JIRA ticket linked, example (case %%). If it is a private issue, just add the case ID without a link.
  • Jira port for the next release set as "Resolved".
• Tests added/changed, if applicable.
  • Functional tests Area_CanDoX, Area_CanDoX_EvenIfYIsTheCase, Area_WhenIDoX_AndYHappens_ThisIsTheResult.
  • Performance tests.
  • Integration tests.
• Docs for new/changed API's.
  • Xmldoc cross references are set correctly.
  • Added explanation how the API works.
  • Usage code examples added.
  • The manual is updated, if needed.

During merge:

• Commit message for squash-merge is prefixed with one of the list:
  • NEW: ___.
  • FIX: ___.
  • DOCS: ___.
  • CHANGE: ___.
  • RELEASE: 1.1.0-preview.3.

After merge:

• Create forward/backward port if needed. If you are blocked from creating a forward port now please add a task to ISX-1444.