Add HD compact grid support to Salt Next

[bhoppers2008]

Resolving this issue will add HD compact grid support to the Salt Next Figma library.

The challenge to resolve here is that HD compact cannot be added as a density, as it won't be available to other components (it's unique to grid).

There are two approaches being explored here:

1. Variable driven approach: A Figma only grid row height variable collection which sets row height to tokens: default or compact (for HD only). Risk: grid row height can be applied to any density grid (ie., row height for any density can be set to the HD compact height)–mitigated by clearly stating 'HD only' token name.
2. Component props driven approach: An additional component to drive height of HD cells only. Risk: needs to be set per header/cell component–mitigated by providing clear guidance and HD compact grid stickers.

[bhoppers2008]

@pseys for reference.

[bhoppers2008]

Current spec row height currently excludes border between rows, so we need to configure ag grid (in code) with +1 number to be on spec. MTK has HD compact correct, but other densities wrong, which they will fix

[mark-tate]

Cortado Goal: Update spec

[navkaur76]

kick off w/ Paul scheduled for 06/08

[navkaur76]

Using variable driven solution. @pseys to add relevant variables for row height in Styles library before the component can be updated.

[origami-z]

Aug 12 - TBD variable library update

[joshwooding]

Aug 14 - @pseys to add a variable to the Figma library.

[origami-z]

Needs result from #3996

[pseys]

Figma variables have been created in a branch and are ready to merge. Waiting on a resolution to #3996 before progressing.

[mark-tate]

Espresso Goal : released by 13th September