Adding Production Instrumentation Reporter tool to Closure compiler

[patrick-sko]

This PR contains the code for the production instrumentation reporter tool. The code was reviewed in a separate PR on a different github repo: patrick-sko/instrumentation-reporter#2.

The minor changes between that PR and this one is I made a change to the unit test. I shrunk the size of the golden files by a lot to be more manageable.

In addition to the unit test changed, I also modified the BUILD.bazel to create a separate Jar file for the reporter.

This PR is the final step of the following feature proposal: https://docs.google.com/document/d/1uvEazsDdX0w4fRhREESvr_w7YX7JYNe27e5bD-CBeGM/edit?usp=sharing

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[patrick-sko]

@googlebot I signed it!

[patrick-sko]

@lauraharker Hey Laura, do you think you would be able to look this over/merge it?

[lauraharker]

Thanks, Patrick. Working sending for internal review now.

[lauraharker]

FYI, I moved the testdata files internally to be in the same directory as ProductionInstrumentationReporterTest.java, since that works better with how the internal Google BUILD files are set up.

No action needed here though.