Brief overview of PR changes/additions

Fixed maps not being removed from memory when profile is closed, which would increase memory use if you opened maps & profiles and then closed them while keeping Mudlet running. Now, closing a profile will properly remove the map data from memory as well.

Motivation for adding to Mudlet

Removes a memory leak, fixes #5897.

Other info (issues closed, discussion etc)

Unlike other fixes which significantly slowed down profile shutdown, this one is instant.

In addition to this, loading another map while playing is also quicker!

Memory leak verified gone by looking at the AddressSanitizer.

/claim #5897