Vars to theme slider

[mrgeorgegray]

• Removes unused @slider-tooltip- vars
• Moves and adds color vars for <Slider /> to default.less

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• Changes for master
• Make sure that you follow antd's code convention.
• Run npm run lint and fix those errors before submitting in order to keep consistent code style.
• Rebase before creating a PR to keep commit history clear.
• Add some descriptions and refer relative issues for you PR.

[codecov]

Codecov Report

Merging #9065 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #9065   +/-   ##
=======================================
  Coverage   85.25%   85.25%           
=======================================
  Files         195      195           
  Lines        4674     4674           
  Branches     1378     1378           
=======================================
  Hits         3985     3985           
  Misses        689      689

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[afc163]

You shouldn't change the original var name which would cause a break change.

[mrgeorgegray]

Sorry, but I couldn't see that @slider-tooltip-color, @slider-tooltip-bg, @slider-tooltip-arrow-width, @slider-tooltip-distance and@slider-tooltip-arrow-color are being referenced anywhere so I thought it safe/good to remove them.

[afc163]

You are right, though @slider-margin is used before.

[mrgeorgegray]

Ahh yes, added it back in 56c1ca9