[JENKINS-74067] Extract inline JavaScript from BuildMonitorView/index.jelly

[yaroslavafenkin]

https://issues.jenkins.io/browse/JENKINS-74067

Testing done

Content Security Policy does not catch the violations on pages without l:layout, so I'm not relying on it here. I've tried manually adding the header on top of the file by adding the following:

<st:setHeader name="Content-Security-Policy"
                  value="default-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: ; script-src 'self' 'report-sample' usage.jenkins.io www.google-analytics.com api.github.com;"/>

Page obviously just falls apart with that header set because of inline scripts.
On the screen recording I'm demonstrating the replacement of makeStaplerProxy by the plugin (for whetaver reason it needs it, angularJS I guess), and showing plugin's basic behaviour like monitoring build statuses and showing build progress.

Before the fix

With the fix we're able to set the CSP rule as shown above and test with it. I've demonstrated that makeStaplerProxy is replaced in the same way as before the fix. And showing that all the build monitoring stuff still works with CSP header set.

After the fix

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For Google Analytics script I've missed it when recording initially, so covered it separately:

Before the fix
After the fix

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue

[basil]

Thanks!