Description

Currently to configure a Jira Data Center connector a password needs to be passed in the API token field of the form.

We should allow users to use Personal Access Tokens instead. Using Personal Access Tokens.

This will require some changes in the way auth headers are built in x-pack/plugins/stack_connectors/server/connector_types/jira/service.ts.

For Jira Cloud, everything can stay the same. For the Data Center, the PAT needs to be passed as Authorization: Bearer <token>.

We should also have a clear distinction in the UI that allows us to know which "kind" of Jira is being used.

The documentation will also need to be updated accordingly.