feat(MenuButton): add component

[jurokapsiar]

Allows opening a "dropdown" menu on left/right click, hover or focus.
Reuses Popup, adds a Menu to its content.

Fixes #345

[codecov]

Codecov Report

Merging #1696 into master will decrease coverage by 0.04%.
The diff coverage is 62.71%.

@@            Coverage Diff             @@
##           master    #1696      +/-   ##
==========================================
- Coverage   69.94%   69.89%   -0.05%     
==========================================
  Files         863      867       +4     
  Lines        7286     7338      +52     
  Branches     2110     2147      +37     
==========================================
+ Hits         5096     5129      +33     
- Misses       2183     2201      +18     
- Partials        7        8       +1

Impacted Files	Coverage Δ
packages/react/src/index.ts	100% <ø> (ø)	⬆️
packages/react/src/components/Popup/Popup.tsx	65.71% <ø> (ø)	⬆️
...ckages/react/src/components/Popup/PopupContent.tsx	95.45% <100%> (+14.5%)	⬆️
packages/react/src/components/Menu/Menu.tsx	71.79% <100%> (+0.74%)	⬆️
...ages/react/test/specs/behaviors/testDefinitions.ts	89.53% <100%> (ø)	⬆️
...ages/react/src/lib/getOrGenerateIdFromShorthand.ts	100% <100%> (ø)	⬆️
...lib/accessibility/Behaviors/Popup/popupBehavior.ts	93.75% <100%> (ø)	⬆️
...ibility/Behaviors/MenuButton/menuButtonBehavior.ts	100% <100%> (ø)
...ages/react/src/components/MenuButton/focusUtils.ts	20% <20%> (ø)
...es/teams/components/MenuButton/menuButtonStyles.ts	33.33% <33.33%> (ø)
... and 6 more

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