* Delete deprecated font tokens.
* Migrate from primaryContent to textPrimary/iconPrimary.
* Migrate from links to textLinkExternal.
* Migrate from secondaryContent to textSecondary/iconSecondary.
* Migrate from accent to textActionPrimary.
- Some uses changed to textPrimary or iconPrimary as necessary.
- Some manual tints removed now that that Sentry is fixed.
* Migrate alert to textCriticalPrimary/iconCriticalPrimary.
* Migrate from brand to textActionAccent/iconAccentTertiary.
* Migrate from background to bgCanvasDefault or text/iconOnSolidPrimary
* Migrate system to bgSubtleSecondary.
* Remove ElementUIColors and obsolete migrated colours.
* Migrate tertiaryContent/quaternaryContent/quinaryContent to Compound.
* Migrate bubblesYou/bubblesNotYou to use Compound.
* Update Compound.
