* Alerting: Update state manager to have immutable state in cache (#95985)
* create a new state and set at the end
* propagate labels datasource_uid and ref_id from current state if it's error
* copy the state when apply to all
(cherry picked from commit 420db99d16)
* Remove unused states variables
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Co-authored-by: Yuri Tseretyan <yuriy.tseretyan@grafana.com>