UI: Fix overflow issues in repo

[silverwind]

• Fix layout overflow in repo file list.
• Fix invisible status icon in file view and commit list. In file view, the icon was moved to the left because I could not figure out a proper fix because of HTML tables.
• Added title attribute to commit messages.
• Fixed two CSS linter warnings in existing CSS.
• Fixed CI variable check in 'make css'.

Fixes: #7180

Screenshots:

[silverwind]

If anyone has a better idea on how to get the icon (and text-overflow) to work correctly on the right side of the file view header, shoot. Couldn't figure it out while testing with Firefox. I imagine it being easier to fix in Chrome as it seems to handle text overflow in tables quite differently than Firefox (which for some reason falls back to display no text at all in some cases).

[silverwind]

Thinking about maybe truncating the commit line to 50 or 72 chars before rendering and making sure the UI has enough space for that so we don't have to rely on wonky CSS-based truncation.

[mrsdizzie]

Looks like Github cuts off at 70 characters(plus an ellipse) which seems reasonable for this.

[codecov-io]

Codecov Report

Merging #7190 into master will decrease coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #7190      +/-   ##
==========================================
- Coverage   41.53%   41.52%   -0.01%     
==========================================
  Files         449      449              
  Lines       61306    61306              
==========================================
- Hits        25462    25456       -6     
- Misses      32490    32497       +7     
+ Partials     3354     3353       -1

Impacted Files	Coverage Δ
models/unit.go	62.16% <0%> (-5.41%)	⬇️
routers/repo/view.go	42.23% <0%> (-1.02%)	⬇️

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[silverwind]

Yeah, will look into doing that, so please consider this PR a WIP.

[lafriks]

Imho that character limit can be done in other PR

[silverwind]

Feel free to merge this now. I will follow up with another PR that does the truncation and moves the icon in the file table to the right again later.