Make `s_is_adapter_wanted` and the elements of `s_config_rumble_enabled`
atomic.

The CPU thread reads `s_is_adapter_wanted` and `s_config_rumble_enabled`
in `Output`, while the host thread writes to them in `RefreshConfig`.

The simplest way to trigger this race is to close the `Settings` window
while playing a game with the adapter active.

GCAdapter: Automatically start and stop thread

This keeps the logic encapsulated inside GCAdapter.cpp so callers don't
have to think about it.

Accomplished using `run-clang-tidy` with `performance-move-const-arg,performance-unnecessary-value-param,modernize-pass-by-value`.

Changed arguments to const references, removed them where inappropriate (e.g. sink parameters). Same with std::move.

Manually reviewed each change to make sure that it makes sense, and do something more appropriate if possible.

GC adapter fixes (hotplugging, claim retries, Dolphin shutdown)

Core: Add SDL Hints settings