Disable close button on tabs if tab size is too small

[luixxiul]

Test plan

Under "QA steps" on #7799 (comment)
#7851 (comment)

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Describe the issue you encountered: if you click the close button of tab whose size is too small, sometimes you click the close button accidently.

Expected behavior: Disable close button on tabs if tab size is too small.

• Platform (Win7, 8, 10? macOS? Linux distro?): Windows 10

• Brave Version: 0.12.8 RC1

• Steps to reproduce:

  1. Open many tabs
  2. Minimize the width of the window
  3. Select any tab carefully not to close it...

• Screenshot if needed:

• Any related issues:

[bradleyrichter]

This sounds like a LHF fix. (low hanging fruit)

@bbondy Can we get this in sooner than 1.0?

[bbondy]

@cezaraugusto mind grabbing this?

[bsclifton]

Change was backed out with #5886 after we noticed positioning of the audio icon being wrong:

The CSS as-is (in tabs.less) is great and works wonderfully... until the window gets smaller than ~520px. I think the changes that were made need to be wrapped with a media query and should only be applied if within the breakpoint that was defined (520px). 😄 Milestone has already been bumped to 0.13.1

[luixxiul]

Reopening based on the feedback by @srirambv and me.

#7799 (comment)

Test 1 fails as the close button is overlapped on the right side of favicon. And the click area is more than the close button causing it to close the tab when clicked on the favicon

Another adjustment of min-threshold for closeTab would be needed.

[luixxiul]

@cezaraugusto I like your last solution quite well 💯 The next step is to fix #2702.