* Alerting: Introduce a Mimir client as part of the Remote Alertmanager
This is our first attempt at making Grafana communicate use Mimir as a backend - it uses a new set of APIs that we've developed on the Mimir side to upload the grafana configuration and alertmanager state so that it can then be ported over.
Codewise, we've introduced a couple of things:
A client to isolate in its own package all the communication that happens with Mimir
A few changes to the remote/alertmanager to include uploading the configuration and state when it starts
A few refactors that align a bit better with the design approach that we're thinking
An integration tests again these newly developed APIs using a custom image
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Signed-off-by: gotjosh <josue.abreu@gmail.com>
Co-authored-by: Santiago <santiagohernandez.1997@gmail.com>
