UI Automation in Windows Console: use UIATextInfo in known-good cases

[codeofdusk]

Link to issue number:

Blocked by microsoft/terminal#6986.
Closes #12130.
Might help #11172.
Supersedes #11495.

Summary of the issue:

Before recent upstream work, NVDA needed a custom TextInfo implementation including workarounds for the console. Notably, it was necessary to restrict the text range to visible content, as the console contained thousands of empty lines which both slowed down diffing and disorientated the user. With the resolution of microsoft/terminal#6986, this is no longer necessary as the console's UIA text range now ends at the last actual character (i.e. no more extraneous empty lines).

This bounding to the visible ranges can sometimes lead to choppy speech output, as full screen refreshes (such as in pagers or full-screen editors) cause text discontinuity, resulting in the diff algorithms losing context about which parts of the text are new. It breaks precedent from the rest of NVDA: in Word or web documents, for instance, the review cursor is not bounded to the visible text and the entire document can be freely explored. Despite the documentation of the scrolling commands in the user guide, the need to scroll consoles in particular, in strict contrast to the behaviour in other applications, has caused user confusion (microsoft/terminal#6453 and private correspondance with various users) and the commands don't work consistently in any case. In microsoft/terminal#6453 (comment) it was pointed out that consoles can have text that appears below the visible content, which is currently inaccessible to NVDA due to bounding.

Description of how this pull request fixes the issue:

• Unifies textInfo workarounds at ConsoleUIATextInfoWorkaroundEndInclusive.
• Switches new consoles (i.e. those where isImprovedTextRangeAvailable) to use the default TextInfo implementation (i.e. no customization at the UIA text range level).
• Deprecates ConsoleUIATextInfo but keeps the name to maintain backwards compat.

Testing strategy:

With NVDA developer info (NVDA+f1), verified that:

• In a console where isImprovedTextRangeAvailable: UIATextInfo is used.
• In a console where not isImprovedTextRangeAvailable: ConsoleUIATextInfoWorkaroundEndInclusive is used.
• In Windows Terminal: UIATextInfo is used.

Also manually verified that new and old UIA console work as expected.

Known issues with pull request:

None.

Change log entries:

== Changes for Developers ==

• NVDAObjects.UIA.WinConsoleUIA.ConsoleUIATextInfo has been deprecated, use NVDAObjects.UIA.UIATextInfo instead. (UI Automation in Windows Console: use UIATextInfo in known-good cases #12425)
  • If specifically accessing an older console (i.e. one where isImprovedTextRangeAvailable is False), continue to use ConsoleUIATextInfoWorkaroundEndInclusive.

Code Review Checklist:

• Pull Request description is up to date.
• Unit tests.
• System (end to end) tests.
• Manual tests.
• User Documentation.
• Change log entry.
• Context sensitive help for GUI changes.

[AppVeyorBot]

See test results for failed build of commit 3489a9c339

[AppVeyorBot]

See test results for failed build of commit 3489a9c339

[codeofdusk]

Closing in favour of a new strategy using #12660.