Cleaned up XML block editors within the editor

[MeyAyre]

Changes:

• Removed unnecessary code that brought the XML block editors up if the level wasn't a droplet level. Now that droplet and blockly code live happily in their own partials there's no need for checks like this anymore.
• Moved the solution block xml editor to the same area as the other xml block editors.
• Made XML block editors collapsed by default (Requested by Mike Harvey)

Before:

After:

[Hamms]

Why are some of the arrows in the "after" screenshot up, and some down?

[MeyAyre]

@Hamms This is something that's been happening with the arrows. They sort of arbitrarily change direction when you click on the collapse trigger.

[Hamms]

Hmm, that's not super helpful of them. Are you tracking levelbuilder issues anywhere? If so, we should add the arrows problem to that list. If not .... we probably should be.