* Fix RuleEditor flaky test for existing grafana managed alert
* Fix RuleEditor flaky test for creating a new grafana managed alert
* Fix tests for cloud rules
* Split tests for different rule types
* Move common clickSelectOption method to helpers
* Remove from RuleEditorCloudRules.test.tsx a repeated cloud rule test
* Move existing grafana rule test case to a new file
* Split RuleEditorCloudRules test: move checking only allowed data sources test case to a new test file
* Re-use common ui const
* Re-use renderRuleEditor method
* Create getDiscoverFeaturesMock to reduce code
