Include Origin/EADesktop version in user agent string

[pg9182]

This will be very helpful for debugging the username (and other auth-related) issues.

[pg9182]

OriginSDK's OriginStartup outputs this to the first char* member of the struct passed as a pointer in the last arg. Need to actually look at where r2 calls OriginStartup and whether the string contains the info we need.

[pg9182]

It appears that tier0 exposes this with Tier0_GetOriginVersionString.