Allow import-roms to match by name in unattended mode

[Missingmew]

When dealing with systems like the PS1 there are a lot of games where CD tracks (which redump lists as individual files) match across multiple releases (sometimes half a dozen).

On import, using unattended mode will currently skip these files. I have enough cases of that happening that doing it by hand is not convenient.

My idea: If a file produces multiple hits and its name matches exactly one of those hits, import the file as that.
In addition (I haven't tested yet if this already works like that), any ROM that is already imported should not be considered again, possibly with an extra flag to re-enable considering all options. That should make dealing with the remains by hand a lot easier and possibly resolve ambiguity in unattended mode if the remaining candidates becomes 1.

In my specific case exact matching would be enough (since I used the DAT file in the first place to produce the mess I have right now from a worse mess from years ago), but for people coming from older naming (such as older DATs possibly) some kind of fuzzy matching would probably improve the automation even further.