## Summary of the Pull Request
Adjusts `DrawGlyphRun` method inside DirectX renderer to restrict text
to be clipped within the boundaries of the row.
## PR Checklist
* [x] Closes#1703
* [x] I work here.
* [x] No tests.
* [x] No docs.
* [x] I am core contributor.
## Detailed Description of the Pull Request / Additional comments
For whatever reason, some of these shade glyphs near U+2591 tend to
extend way above the height of where we expect they should. This didn't
look like a problem in conhost because it clipped every draw inside the
bounds. This therefore applies the same clip logic as people don't
really expect text to pour out of the box.
It could, theoretically, get us into trouble later should someone
attempt zalgo text. But doing zalgo text is more of a silliness that
varies in behavior across rendering platforms anyway.
## Validation Steps Performed
- Ran the old conhost GDI renderer and observed
- Ran the new Terminal DX renderer and observed
- Made the code change
- Observed that the height and approximate display characteristics of
the U+2591 shade and neighboring characters now matches with the conhost
GDI style to stay within its lane.
Certain DirectX features are unavailable on windows 7. The important ones as they are used in the DX renderer are color font rendering and fallback font support. Color fonts did not exist at all on windows 7 so running basic glyphrun rendering should work just fine.
Fallback font support was not exposed to the user in windows 7, making dealing with them difficult. Rather than try to get some workarounds to properly enable it I have opted to just conditionally disable the support on windows 7.
