* Define EvaluationContext
* Refactor ConditionEval to use new context struct
* Refactor QueriesAndExpressionsEval to use EvaluationContext
* Remove dead field from AlertExecCtx
* Refactor Validate to use EvaluationContext
* Get rid of privately used AlertExecCtx
* Move EvaluationContext to new file and add helper
* Add builder pattern and bind rule info to context
* Extract header logic and add rule UID header
* Fix missing call