Force LBP PSP to receive OK from certain endpoints

[Toastbrot236]

This forces certain endpoint methods to always return OK to LBP PSP, even if the actual response status is not OK, to not cause the client to abort login or softlock itself. The endpoints I modified for this are:

• Grief report uploads
• Score uploads
• Play uploads
• Level star rating uploads
• Level tag uploads

Also, I added unit tests to ensure that both these and the level/user hearting endpoints do always return OK to PSP. I initially wanted to use a Service for this which would overwrite the response data in ListenerContext, but it turns out that Bunkum, for some reason, only writes the endpoint method response there after calling Service.AfterRequestHandled(), so I just modified the endpoint methods in the end. This means that non-OK responses from services (e.g. rate-limits and auth failures) will still be returned to PSP, but I hope that won't be an issue, and I don't consider this to be important enough to put more effort into.

[Toastbrot236]

I noticed that RoleService might still be a problem. That should be taken care of in a separate PR though, to not make this one too large, but an idea to handle that might be to use an attribute after all.