Fix regression where many blank lines were reported in browse mode

[SaschaCowley]

Link to issue number:

Fixes #16554

Summary of the issue:

#16471 introduced a regression whereby many blank lines were reported in browse mode.

Description of user facing changes

Extraneous blank lines are no longer reported in browse mode.

Description of development approach

Updated checks in gecko_ia2.cpp:

• Check that the length of name is non-zero (SysStringLen returns 0 if the BSTR passed is null)
• Added check that description's value is not the empty string, as checking that it has a value is necessary but not sufficient.

Testing strategy:

Tested reading the PR for #16471 as described in #16554. Also tested as described in #16471 to ensure changes did not break the new behaviour.

Known issues with pull request:

N/A

Code Review Checklist:

• [x] Documentation:
  • Change log entry
  • User Documentation
  • Developer / Technical Documentation
  • Context sensitive help for GUI changes
• [x] 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.