Play can only be used when a game is selected and emulation is not
running. Start can be used when a game is selected (to start from
cold boot) or when emulation is running (to start from a savestate).
https://bugs.dolphin-emu.org/issues/11826
Doing pretty much anything in the controller config breaks NetPlay
(desync and/or deadlock), as saving the settings reconfigures
controller interfaces, which NetPlay doesn't expect.
Previously we wouldn't indicate if saving or loading these files
happened to fail. In some cases we'd only print out to the logger, but
this is a pretty poor way to tell a user of the interface that something
went wrong in a direct way (the logging messages aren't able to be localized
either).
