These styles are not going to be needed in the main menu so are
not generic. Moving to the PageTools component.
Bug: T317899
Change-Id: I17b8ecd645c593c0368ea158265dbf8f6a575345
This patch involves cached HTML changes
- Replace '-content-container' id with '-unpinned-container'
- Replace '-content' id with '-pinnable-element'
- Rename pinnableHeader.js to pinnableElement.js
- Replace PinnableDropdownContents.mustache with PinnableElement/Open.mustache and Close
- Add PinnedContainer/Open & Close and UnpinnedContainer/Open & Close
- Rename .vector-dropdown-content to .vector-pinnable-element
- Add new PinnableElement.less stylesheet
Bug: T318013
Change-Id: I85aec387f87126a17e760fd9fd10e10572ff3152