[BUGFIX] Prometheus: Propagate headers to the @prometheus-io/codemirror-promql package

[th3M1ke]

This pull request introduces several enhancements and new features to the Prometheus client and its integration with CodeMirror. The most significant changes include adding support for fetching Prometheus server flags, creating a CodeMirror Prometheus client adapter, and updating various components to utilize the new adapter.

Enhancements and New Features:

• Support for Prometheus Server Flags:

  • Added FlagsResponse type to prometheus/src/model/api-types.ts.
  • Introduced flags method in PrometheusClient interface and implemented it in prometheus/src/model/prometheus-client.ts. [1] [2]
  • Updated prometheus/src/plugins/prometheus-datasource.tsx to use the new flags method. [1] [2]

• CodeMirror Prometheus Client Adapter:

  • Created createCodeMirrorPromClient function in prometheus/src/model/prometheus-client.codemirror-adapter.ts.
  • Updated PrometheusTimeSeriesQueryEditor to use the new CodeMirror Prometheus client. [1] [2] [3]
  • Updated PrometheusPromQLVariableEditor to use the new CodeMirror Prometheus client. [1] [2] [3]

Resolves: #78

[Nexucis]

I don't see why do you need to implement the method flag. It's not used in the plugin 🤔

[th3M1ke]

Thanks for your feedback! 🙏 The method flag isn't used in the Perses Prometheus client, but it is required for the Codemirror one. I thought it would be a good idea to keep the clients consistent and aligned in structure. However, if you prefer, we can mock it instead

[Nexucis]

Oups sorry for the time it took to come back to you and thank you for pinging me on slack.

So I would prefer to mock it for the moment. If at some points it's necessary we can finally implement it, it won't cost that much.

On another topic, I don't get how this change can fix the issue you raised (#78). Propagating the headers is not the job of the plugin but the job of the proxy on the backend side. So this fill weird this PR is fixing that.

Finally, can you

• sign your commit following the DCO procedure you can find in the DCO job ?
• rebase your PR to get the last changes of the CI that should unlock some issue we currently have with Cuelang
• fix all issues raised by the linter

Thanks !