Add support for configurable plot width/height

[markus-franke]

Jira: JENKINS-59237

What has been done

1. Removed fixed plot dimensions from PlotReport
2. Added plot configuration parameters "width" and "height" including associated documentation

How to test

1. Create a pipeline or freestyle project
2. Setup Build step for plot plugin
3. Specify width/height parameters
4. Run a build
5. View generated plots in desired dimension

Checklist

• Git commits follow best practices
• Build passes in Jenkins -> 11 successful steps but the last one mysteriously fails, this happened also for previous merge requests, probably a CI/CD configuration issue
• Appropriate tests or explanation to why this change has no tests -> I am new to the project and don't have a clue how this could be tested automatically. I just tested it manually by building the Maven target hpi:run and setting up plot jobs manually within the test instance
• Pull Request is marked with appropriate label (see .github/release-drafter.yml) -> I don't seem to have permissions to add labels to this PR.
• JIRA issue is well described (problem explanation, steps to reproduce, screenshots)
• For dependency updates: links to external changelogs and, if possible, full diffs

[moo-the-cow]

I have exactly the same issue. width, height argument does not affect the plot (it should according to documentation).
having like 20 labels on the plot, you cannot properly see anything at default width/height. the whole purpose of the plugin is to visualize data. I'd love to get this prioritized.
Thank you

[nvkhoi112358]

I would love to see this in the next version.

For now, the only way to enlarge the plot is modify the querystring getPlot?index=0&width=750&height=450, not configurable through groovy script.

[MarkEWaite]

@markus-franke sorry for the long delay reviewing the pull request.

I tested the pull request with Jenkins 2.462.3 and was unable to have it actually apply the values for width and height. I created a freestyle project, defined the plot height and width, and ran the job several times. The plot width and height were unchanged on the display. The plot width and height were not retained in the freestyle job definition form. When I configured the job again, the width and height fields were empty.

[MarkEWaite]

Needs more work to assure that the plot width and height configuration is saved when the form is saved and that the plot width and plot height are used when generating the plot.