One playground to rule them all

[SimonGenin]

In an effort to improve the owl ecosystem, some work can be done to improve the playground.
In a perfect world, it should be nice to use and could be shared.

It is, in its current state, usable. Don't forget to npm install for the monaco editor.

• Switch to monaco editor
• Tweak the settings to make it perfect
• See if we can give it better autocompletion (Like it would know @odoo/owl)
• Move it to own repository and switch to typescript ? Only keep the resulting /dist to the owl repo.
• Add a backend (maybe firebase to avoid hosting our own ?)

Add old behavior back

• Make it resizable

• Make it so we can see both xml and js at the same time

• Ctrl z doesn't work if we switch from js / css / xml. We can probably fix this.

• Clean the code nicely to make it easier to upgrade.

Removed:
Downloadable files