Alerting: Use a completely isolated context for state history writes (#64989)
* Add fresh context with timeout and same log properties, re-derive logger
* Unify timeout constants
* Move ctx after shortcut that got added through rebasing
* Unify timeouts
* Port opentracing's SpanFromContext and ContextFromSpan to the grafana tracing package
* Support both opentracing and otel variants
* Better document why we're creating a new ctx
* Add new func to FakeSpan which was added after rebase
* Support grafana-specific traceID key in both tracer implementations
(cherry picked from commit fb520edd72)
Co-authored-by: Alexander Weaver <weaver.alex.d@gmail.com>
c7cc68649d