Add VSC UI Toolkit

[AngelMunoz]

This PR attempts to ease a little bit working with webviews and to also enable the usage of the vscode ui toolkit.

I didn't go as far as thinking what else can we use webviews for but I at least switched the table for the watcher for the datagrid included in the toolkit.

There are a few observations I have on this regard

• I had to include the toolkit js file on the release directory

  This might be able to be solved with a few tweaks on the webpack config but I couldn't figure it out

• I tried using Feliz.ViewEngine but I decided to stick with strings

  The vscode toolkit would require the proper bindings for Feliz.ViewEngine and that might be quite a lot of work, thankfully Alfonso has already make it easier to work with html/css/js strings within F# files thanks to his extension so I felt it was actually easier to work with inline strings

• Webviews could be made with an project outside src

  After my comment on Consider managing FSI sessions in FSAC directly #1720 I found out that yeah we could use external websites for the webviews but they have to live in iframes which make things quite complicated, what what we could do is to have a separate project (Fable.Lit or Feliz based one) that outputs the final bundle to the release directory, later on we would build the index by hand (as we're doing it now) but including the scripts within the release directory. That complicates infrastructure though so it might be just too much for the project to handle at least right now.

In any case Feel free to close this PR if this is not needed it was more to explore approaches and see what worked and what not, I thought it could be useful so I ventured to open this.

[baronfel]

Haven't looked at this in detail, but I am looking at moving to esbuild in #1684/#1713 so maybe that would be easier?

[baronfel]

Thanks! I like the contribution, its a nice styling and UX enhancement for sure. I'd like to see if the packaging issue can be fixed - ideally we'd be able to NPM reference the toolkit and let the build take care of bundling the output.

[baronfel]

super weird - can you add not a reference to the toolkit and let webpack pull it in (I'm just skimming their getting started docs)

[AngelMunoz]

I tried following the getting started from the toolkit but their getting started assumes the directory where you launch your extension is the root of the project (hence why it had node_modules available), in our case the release directory is the root so we don't have access to node_modules, we'd likely need to do some webpack magic to pull this script at dev/build which was the part I couldn't figure out

[baronfel]

Gotcha. I'd also be ok longer term with removing the release split. It's just confusing IMO.

[AngelMunoz]

give me a chance to look over this week/next weekend to remove webpack from the toolchain
technically we don't need it anymore the electron version handles all of the JS Fable emits, so we would likely need something like rollup which helps us with minification and tree-shaking, watch mode and other helpful stuff

I don't really think we need vite/esbuild because we don't really run in a browser context we're basically just doing node stuff under the hood

[Krzysztof-Cieslak]

I like this, let's merge it.