Add rate limiter to api

[smallketchup82]

this should be relatively easy. just search up asp.net rate limiter

also the use for this is making sure the api doesn’t suddenly get flooded with requests & overwhelm the server.

the database can’t be used concurrently so most of galaxygpt is still being run synchronously. we need to limit the amount of requests to something high enough that it won’t disrupt normal usage, and low enough that it’ll filter out spam