Bug - Select/Dropdown - menutoggle doesn't receive focus on menu close

[nicolethoen]

For the newly promoted Select & Dropdown components, we need to ensure that browser focus returns back to the MenuToggle:

1. when an MenuItem has been selected and results in the menu closing
2. when the 'escape' or 'tab' keyboard is used to close the Menu

This is a regression from our deprecated Dropdown and Select implementations

[kmcfaul]

Will open a separate PR for dropdown's fix