Add authentication methods for API access

[petethepig]

Now that we have OAuth support for viewing the data we need to add authentication support for API clients, particularly:

• client integrations
• grafana datasource

Currently, when set up with OAuth client integrations bypass authentication altogether (/ingest doesn't do authentication), and grafana panel can't access data at all. We need some way of setting some API keys for both.

[eh-am]

For grafana datasource we need to do the following

1. add the input to support API_KEY https://github.com/pyroscope-io/pyroscope/blob/main/grafana-plugin/datasource/src/ConfigEditor.tsx#L27-L39

2. update the fetch calls to use that API_KEY as header https://github.com/pyroscope-io/pyroscope/blob/main/grafana-plugin/datasource/src/ConfigEditor.tsx#L27-L39

[kolesnikovae]

• Documentation: https://github.com/pyroscope-io/docs/pull/43
• Rust: https://github.com/pyroscope-io/pyroscope-rs/issues/16.
• Grafana datasource plugin: https://github.com/pyroscope-io/pyroscope/pull/844
• Go, Python, Ruby, Java, exec, connect, agent already support this.

Please review the docs and Grafana plugin PRs.

[petethepig]

Released in 0.10.2