Add option for enabling threaded loading and better loading screen

[XenuIsWatching]

Add a option in the "other settings" to enable threaded gamelist loading. This option already existed in es_settings, there just wasn't an easy to set it without manually editing the file
This gives better performance when parsing multiple large gamelists, and will give a much faster start up time

threaded-loading.-.Made.with.Clipchamp.mp4

[mostly vibe coded this]

[pjft]

Thanks for sending this over. There seem to be more changes than just the option being added. Can you elaborate on them?

[XenuIsWatching]

Thanks for sending this over. There seem to be more changes than just the option being added. Can you elaborate on them?

That is just getting the 'Loading screen' working with the progress bar being updated with multiple threads. There was some work to get that also displaying vertically where it will list out each platform is scanning for each thread.

[pjft]

I tested it and it looks good from my end.

If nobody else has any concerns, I'm happy to merge.

[cmitu]

I'm not a fan of displaying multiple systems at once during loading, but that's subjective.
As long as the default option is kept the same (i.e. off), it's ok with me 👍.

[pjft]

I agree with that take.
When Threaded Loading is on, it now shows all systems like that - whereas in the previous version it only showed one.
I'd agree with either splitting the PRs, or reverting that part.