[Retire] Rose::Dropdown (#2858)
* remove dropdown styling
* remove rose/dropdown child component integration tests
* refactor tests, delete tests
* remove rose dropdown component from addons/
* refactor tests, delete tests
* run yarn format
* remove additional rose dropdown files from addons
* remove ref to rose dropdown from readme
* remove skipped test, comment states no longer relevant
* remove unused ref to rose-header-dropdown selector
* refactor tests using .rose-dropdown selector, cleanup
* run yarn format
* add selector to commonSelectors, refactor more tests
* nest .hds-dropdown selector in place of .rose-dropdown
* revert @use dropdpwn
* remove line, styling already applied on btn selector
* removed unused dropdown-radio-btn selector
Lauren
5555603a5c