AGS 4: an directory-based alternative to "Import existing room"

[ivan-mogilko]

Since in AGS 4 rooms are now saved as directories with multiple files in it, "Import existing room" command which imports a compiled room becomes obsolete, and only worth keeping for backwards compatibility (importing rooms from old game projects).

We need a new "Import" command that would import existing Room directory instead.

Such command might also help if room dir got "detached" from the project for some reason (not saved, or error during project save), or copied there by hand.

Proposal:

• Old "Import existing room" is renamed to "Import compiled room" (or similar title);
• Make new "Import existing room" that requires user to select a room directory. Tests that this directory has minimum of room contents (afaik "data.xml" is the minimal requirement, the rest may be generated). If the dir exists inside same project then simply adds a room object in game, but keep the dir. If the dir is elsewhere, then it gets copied.
• Optionally, if the dir contains extra unknown files, ask whether to copy all files or only standard room files.