Fixed problem when some visual artifacts may appear after resize

[lenenel]

I have menu hidden by default and observed visual artifacts after pressing Alt. Menu appears after I press Alt and editor area is resized, but not the whole area is redrawn, so I see 2 neovim's status bars. I also can reproduce similar behaviour by resizing Oni window.
See video with this problem

After investigation I've found that method CanvasRenderer.redrawAll is called before neovim is really resized so it draws state of neovim before resize. So I've changed code so it called only when Promise returned by NeovimInstance.resize method is resolved. Which is actually Promise returned by Session.request method, so should be resolved when neovim finished resizing itself.

[codecov]

Codecov Report

Merging #2578 into master will not change coverage.
The diff coverage is 0%.

@@           Coverage Diff           @@
##           master    #2578   +/-   ##
=======================================
  Coverage   45.44%   45.44%           
=======================================
  Files         353      353           
  Lines       14445    14445           
  Branches     1885     1885           
=======================================
  Hits         6564     6564           
  Misses       7657     7657           
  Partials      224      224

Impacted Files	Coverage Δ
browser/src/Editor/NeovimEditor/NeovimRenderer.tsx	8.69% <0%> (ø)	⬆️
browser/src/neovim/NeovimInstance.ts	5.47% <0%> (ø)	⬆️

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[CrossR]

Sorry for the delay! If nobody else has got this, I'll take a look at the Weekend.

[CrossR]

Tests have all passed and I didn't see any issues when I used this for the past few days!

Cheers for the contribution @lenenel!