There are no longer any common menu styles. These are moved to the legacy
skin and new rules are added to the dedicated components.
Change-Id: I1bf26bfb29bb495ee65e983fad60122007f62698
Removes the common MenuPortal.lesss code and splits it into
Vector 2022 and Vector legacy in anticipation of changes to
the sidebar in Vector 2022.
Bug: T317583
Bug: T319348
Change-Id: I57d3dc3458a7d6a4877170c26c88ca9222e00ff7