Allow a non-persistent DatabaseProfile option

[alunmj]

If the DatabaseProfile created by New-KeepassDatabaseConfiguration could be stored into variables, rather than files, scripts could be written to dynamically handle kdb/kdbx files without having to write to the store.

[alunmj]

Example use case: I have a backup directory of several kdbx files produced over the last few years. Before cleaning them up, I'd like a summary of what changes happened between versions (just "this password changed on such-and-such date between these files"). It really doesn't make much sense to write config to a file only to remove them a few minutes later.