I added `enum class` to one thing and decided that that was quite enough
before disabling the `enum class` warning.
Looks like 16.8 made more map/vector operations noexcept, so we have to
re-annotate to remain compliant.
## Summary of the Pull Request
When resizing the window title, a GDI object would be leaked. This has to do with our island message handler using `wil` to track these objects and `wil` having a bug.
## References
microsoft/wil#100
## PR Checklist
* [x] Closes#5949
* [x] I work here.
* [x] Tested manually
* [x] Doc not required.
* [x] Am core contributor.
## Validation Steps Performed
* [x] Added the GDI Objects column to Task Manager, set the Terminal to use the `titleWidth` size tabs, then changed the title a bunch with PowerShell. Confirmed repro before (increasing GDI count). Confirmed it's gone after (no change to object count).
## Summary of the Pull Request
1) Improves the performance of word-recognition operations such as word
navigation in UIA and selection.
2) Fixes a bug where attempting to find the next word in UIA, when none
exists, would hang
3) TraceLogging code only runs when somebody is listening
## Detailed Description of the Pull Request / Additional comments
- The concept of a delimiter class got moved to the CharRow.
- The buffer iterator used to save a lot more information than we needed
- I missed updating a tracing function after making GetSelection return
one text range. That is fixed now.
## Validation Steps Performed
Performed Word Navigation under Narrator and NVDA.
NOTE: The release build should be used when testing to optimize
performance
Closes#4703
