[9.0]Complete Angular removal - annotation editors

Initially discussed in this thread https://raintank-corp.slack.com/archives/CPXKS6FB5/p1644573798235659 Soft deadline: Grafana 9.0 Hard deadline: Grafana 10.0 @ivanahuckova completed analysis on the annotation editors [HERE](https://docs.google.com/document/d/1pG5NqohJgUz3su1B7-h015DBkJMWxGDts-l5tS6Fqwk/edit). Example of replacement of angular editor with react editor: https://github.com/grafana/grafana/pull/47781 Plugins to remove Angular from: (please replace the below with links to the child issues) - [x] https://github.com/grafana/grafana/issues/48325 - [x] https://github.com/grafana/grafana/issues/48326 - [x] https://github.com/grafana/opensearch-datasource/issues/28 - [x] https://github.com/grafana/plugins-private/issues/989