Dropdown: Add tooltip menu item ability

[kevinparkerson]

Fixes #2223

Had an issue with menu links not getting the appropriate styles once wrapped with a tooltip due to SLDS targeting .slds-dropdown__item > a. For a workaround I checked to see if tooltipMenuItem was present and if so inject copies of the styles that apply to the wrapped links. Obviously not the ideal solution but it works... if you have other ideas feel free to mention them!

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[interactivellama]

Yeah, that styling is a little hairy. I think it's an OK solution for work around the design system. I can't think of another way the moment.

[interactivellama]

Looks good! Thanks @kevinparkerson .