Add rate limiting to `BlizzardClient`

[Ernest314]

Not quite sure how to implement this.

The official docs state a limit of 36,000 requests/hr, and a burst limit of 100 requests/sec (long-term average of 10 requests/sec).

[Ernest314]

Check with the API discord on how rate limiting is implemented (e.g. sliding window, buckets, tokens, etc.).

[Ernest314]

.NET 7 comes with a ratelimiting library: https://learn.microsoft.com/en-us/dotnet/api/system.threading.ratelimiting?view=aspnetcore-7.0

Better docs:

• https://devblogs.microsoft.com/dotnet/announcing-rate-limiting-for-dotnet/
• https://learn.microsoft.com/en-us/dotnet/core/extensions/http-ratelimiter