Fix MathJax inline fields flickering in Live Preview

[RyotaUshio]

Hi, I noticed that when I used an inline math like $f(x)$ as the value of an inline field, it caused this annoying flickering for every keystroke in live preview.

Screen.Recording.2023-10-07.at.14.53.54.mov

I've identified the root cause of the vertical movement as the implementation of renderCompactMarkdown, so I've fixed it. Now the flickering is still there, but much less annoying:

Screen.Recording.2023-10-07.at.15.07.20.mov

I will try to eliminate the flickering entirely by reviewing the updating process of the decorations, but for now, this should help as a quick fix.

Please let me know if you have any concerns.

Thank you!

[RyotaUshio]

This PR also fixes the bug where an inline query breaks the line number gutter when the field's value is a MathJax expression. Here's a demo:

Before (52fcd0b):

Screen.Recording.2023-10-07.at.18.33.46.mov

After (5789f9b):

Screen.Recording.2023-10-07.at.18.31.48.mov

[RyotaUshio]

Update: I've written the decoration updating process, inspired by lp-render.ts.

Now, there's no flickering MathJax inline field!

Screen.Recording.2023-10-08.at.2.01.41.mov