Implement timeseries-aware / Prometheus-native rate limiting functionality

AC

Create / verify timeseries aware / Prometheus native rate limiting functionality. With Remote write, we can't afford huge # of timeseries that can reach the service as part of a single service write request.

kakkoyun My understanding is that Gubernator support rate limting at the API end point level , can not verify # of timeseries being written as part of a write request. WDYT ?