feat(dropdown): Add dropright and dropleft direction support

[jacobmllr95]

This commit adds support for dropright and dropleft directions for the dropdown component.

Closes #2108.

[codecov]

Codecov Report

Merging #2117 into dev will increase coverage by 0.03%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##              dev    #2117      +/-   ##
==========================================
+ Coverage   64.71%   64.75%   +0.03%     
==========================================
  Files         156      156              
  Lines        2945     2948       +3     
  Branches      807      810       +3     
==========================================
+ Hits         1906     1909       +3     
  Misses        752      752              
  Partials      287      287

Impacted Files	Coverage Δ
src/mixins/dropdown.js	7.14% <ø> (ø)	⬆️
src/components/dropdown/dropdown.js	100% <100%> (ø)	⬆️
src/components/tooltip/index.js	100% <0%> (ø)	⬆️
src/components/popover/index.js	100% <0%> (ø)	⬆️

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[tmorehouse]

Thanks!