Emmet: Implement Reflect CSS Value in emmet extension

[ramya-rao-a]

Use new emmet modules for implementing "Reflect CSS Value" feature in the emmet extension

The last of the emmet features to be implemented in the emmet extension.
https://docs.emmet.io/actions/reflect-css-value/
Woohoo!

cc @jens1o @vvs @@smlombardi give this one a try in tomorrow's Insiders (July 25)

[vvs]

Hi @ramya-rao-a , this feature does work with CSS files, but not with SCSS ones. :(

[smlombardi]

I never use this feature with scss since I always have a process to run Autoprefixer to add all the alternates as needed.

[jens1o]

Can reproduce what @vvs said.

[ramya-rao-a]

@vvs @jens1o Silly me, the command was still using the old implementation (which didn't support scss)

I have made the change to use the right command in the new extension. Should be out in tomorrow's insides.

[jens1o]

Okay, happy to test that. :)

[vvs]

The latest insiders build works fine w.r.t. this feature for me, including SCSS. 👍

[jens1o]

Also working fine for me. :)

[ramya-rao-a]

perfect, thanks!