* vmalert: fix mistake with object reuse while parsing response
During the refactoring, the wrong optimisations was applied in
parse function which caused metric fields reset. The change removes
optimisation.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1369
* vmalert: add test to cover multiple metrics in one response
* vmalert: support rules backfilling (aka `replay`)
vmalert can `replay` configured rules in the past
and backfill results via remote write protocol.
It supports MetricsQL/PromQL storage as data source,
and can backfill data to remote write compatible
storage.
Supports recording and alerting rules `replay`. See more
details in README.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/836
* vmalert: review fixes
* vmalert: readme fixes
