Add save/load to Custom Team Mappings

[11EJDE11]

When setting custom team mappings, the client will now save/load the values. Only applies to host or skirmish.
Also fixes an issue where for a non-host, the wrong preset would be chosen (always showed as either the first non-custom item or Custom).

Saves in UserINISettings (RA2MD.ini) like:

[TeamStartMappings]
fb2631acdc4728f0dd569ad57dc07edfe89cf736=A,A
a5af19e682d41fbe185a9879ec43785526203346=A,A,B,B,C,C,D,D
6cbdedbec3a190cf3675829715024e1ead54e7b6=A,A,x,A,B,x,B,B
f17d9f67057e32994a760f41a3bd1eb25d26a25c=A,A,B,A,B,B
ccff58c63db1d295480f0cc79d914c5d704b0f84=A,A,A,A,B,x,B,B
0dc540f6f57bc15da1617166b8858fb45953ef15=A,B,C,B,A,C,B,D

[github-actions]

Nightly build for this pull request:

• artifacts-TS.zip
• artifacts-YR.zip
• artifacts-Ares.zip
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[MahBoiDeveloper]

Nice idea, but I suggest for now there also needs to be a Reset To Default button to remove map team assignments. What do you think?