Add GitHub branch and pull request info to the 'Details' widget

[janfaracik]

2.504.1 introduced a new Detail API, allowing core and plugin developers to attach details and groups to objects in Jenkins. This is currently only used by Run in core.

This PR adds relevant Git info to ScmDetailGroup, provided by scm-api-plugin.

Description

For branches show:

For pull requests show:

Submitter checklist

• Link to JIRA ticket in description, if appropriate.
• Change is code complete and matches issue description
• Automated tests have been added to exercise the changes
• Reviewer's manual test instructions provided in PR description. See Reviewer's first task below.

Reviewer checklist

• Run the changes and verify that the change matches the issue description
• Reviewed the code
• Verified that the appropriate tests have been written or valid explanation given

Documentation changes

• Link to jenkins.io PR, or an explanation for why no doc changes are needed

Users/aliases to notify

[janfaracik]

Opening for review to get thoughts.

Is the information we show the right information - e.g. is commit hash needed?

Is my usage of the API correct/are there more efficient ways of doing this.

[timja]

It looks good to me, would be nice if some of this could be centralised in e.g. git plugin or scm-api but I think its difficult because of all the special casing needed by pull requests.

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I think there should be some test coverage though.

[janfaracik]

Good for review, will need squashing.

[timja]

Approving the code as-is it works and looks good, one discussion point I think that should be looked at.

[timja]

@jglick possible to check this please?

[jglick]

will need squashing

Just saw this. 😀 Not a problem I think.