* Alerting: Persist silence state immediately on Create/Delete
Persists the silence state to the kvstore immediately instead of waiting for the
next maintenance run. This is used after Create/Delete to prevent silences from
being lost when a new Alertmanager is started before the state has persisted.
This can happen, for example, in a rolling deployment scenario.
* Fix test that requires real data
* Don't error if silence state persist fails, maintenance will correct
* Alerting: Implement ApplyConfig for remote primary mode (forked AM)
* add TODO for saving the config hash in other config-related methods
* fix bad method receiver name (m -> am)
* tests
* add mutex
* remove sync loop
* Alerting: Add an empty Forked Alertmanager
* Alerting: Add methods for silences to the forked Alertmanager
* check for errors in tests
* make linter happy
* Alerting: Add methods for alerts to the forked Alertmanager
* Alerting: Add methods for receivers to the forked Alertmanager
* Alerting: Add TestTemplate method to the forked Alertmanager
* make linter happy
* separate into both forked AMs
* fix tests
* Alerting: Add lifecycle methods to the forked Alertmanager
* Alerting: Add an empty Forked Alertmanager
* Alerting: Add methods for silences to the forked Alertmanager
* check for errors in tests
* make linter happy
* Alerting: Add methods for alerts to the forked Alertmanager
* Alerting: Add methods for receivers to the forked Alertmanager
* Alerting: Add TestTemplate method to the forked Alertmanager
* make linter happy
* separate into both forked AMs
* fix tests
* Alerting: Add an empty Forked Alertmanager
* Alerting: Add methods for silences to the forked Alertmanager
* check for errors in tests
* make linter happy
* Alerting: Add methods for alerts to the forked Alertmanager
* Alerting: Add methods for receivers to the forked Alertmanager
* make linter happy
* separate into both forked AMs
* fix tests
* rename testErr -> expErr
* Alerting: Add an empty Forked Alertmanager
* Alerting: Add methods for silences to the forked Alertmanager
* check for errors in tests
* make linter happy
* Alerting: Add methods for alerts to the forked Alertmanager
* make linter happy
* separate into both forked AMs
* rename testErr -> expErr
* Alerting: Add an empty Forked Alertmanager
* Alerting: Add methods for silences to the forked Alertmanager
* check for errors in tests
* make linter happy
* make linter happy
* Alerting: Add methods for silences to the forked Alertmanager
