[F.R] Discord Rich Presense SDK.

[Danik2343]

The last pull request (in 2020) was cancelled because RPC was deprecated, but Discord has a new SDK. Social and Embedded.

[YoshiRulz]

For reference, CPP implemented this in GSE, see here.

[CasualPokePlayer]

The official SDK is junk for our purposes.

The old Discord-RPC implementation was made in C++ with a C API available, and was MIT licensed with full source code available, so emulators generally used it. The Discord GameSDK actually just has functionality locked behind native libraries (probably C++ again), without any available source code and no FOSS license, just API headers. As such, pretty much all emulators have kept to the old Discord-RPC implementation, as many of them cannot use the newer Discord GameSDK as it's just not GPL compatible. Likewise, I don't think we should be using the Discord GameSDK at all. Using the DiscordRichPresence library seems better considering its wide usage (going off NuGet numbers) and not deprecated status and not needing to pull in native libraries.

(GameSDK was deprecated since this comment, but the new "official" SDK has the same problem, also Discord liking to just deprecate their SDKs and force on newer SDKs that really ultimately do the same thing for our purposes is good reason to avoid them)

What I implemented for GSE is DiscordRichPresence, a third party library (which I modified to use System.Text.Json but that's besides the point), not the official SDK. It's fairly trivial to implement anyways, if we want we can just implement a basic implementation for now before bikeshedding on a "better" implementation. (And for Telemetry concerns, just don't enable it by default and popup a message when the user tries to enable it notifying what gets sent (it's really not much information in the first place frankly, and is only as much as we're sending to Discord via IPC in the first place)).