This removes the existing endpoints and replaces them with /theme.
/theme/:id - return a theme bundle containing all styling from this USER theme and any parents.
/theme/:engine/:id - return a theme bundle containing all styling from this STATIC theme and any parents
The theme bundle returns a marshalled JSON object containing:
styles - an array of strings representing the collected styles in loading order
snippets - an array ( currently empty ) of collected snippets.
The various bits of theme rendering code for <style> an style <link> have been swapped out with an 'onDidMount' call that loads the thendpoint and appends a series of <style> blocks to the brewRender's head.
This loses some caching advantages, but probably won't matter in the long run.
rename `getStaticTheme` to `getStaticThemeCSS`
rename `getBrewThemeWithCSS` to `getBrewThemeCSS`
rename `getBrewThemeParent` to `getBrewThemeParentCSS`
to avoid confusion with other "get" endpoints like `getBrew`, and unify naming for endpoint functions that return CSS.
Simplify `isStaticTheme` function (getting the parent theme is handled elsewhere)
Ended up being a fairly straightforward change. A few ternaries got smooshed or inverted. Passes builtin and local tests. Need to compare on the test instance.
Move the Static Theme shortcut to getBrewThemeWithCSS to drop an unneeded URL load.
Change the comment in the CSS to refer to the shareURL for the theme
instead of its name if it is a user theme.
