Only report captions when entering and exiting them

[SaschaCowley]

Link to issue number:

Fixes #14874

Summary of the issue:

NVDA reports the word "caption" before every element in a figcaption element, or before each line in same when navigating by line in browse mode.

Description of user facing changes

NVDA now reports "caption" only when first entering a figure caption, and "out of caption" when leaving it.

Description of development approach

Changed textInfos.ControlField.getPresentationCategory to return PRESCAT_CONTAINER when its role is controlTypes.Role.CAPTION .

Testing strategy:

Manually tested in Firefox with my figure example webpage

Known issues with pull request:

None

Code Review Checklist:

• [x] Documentation:
  • Change log entry
  • User Documentation
  • Developer / Technical Documentation
  • Context sensitive help for GUI changes
• [ ] Testing:
  • Unit tests
  • System (end to end) tests
  • Manual testing
• [x] UX of all users considered:
  • Speech
  • Braille
  • Low Vision
  • Different web browsers
  • Localization in other languages / culture than English
• [x] API is compatible with existing add-ons.
• [x] Security precautions taken.