Better, faster, more debugging info

[dpp]

💻 Description of Change(s) (w/ context)

Added lock contention detection with additional context to figure out the context (depth of container descent)

Improved the way back-references (contained by, etc.) handled to make things much more efficient.

🧠 Rationale Behind Change(s)

There were a bunch of issues around handling large sets of JARs that contained a lot of the same class files.
The number of Items per minute would decline as there were more Items processed.

So, I added detection for row-level lock contention.

Turns out there was a lot of lock contention, although lock contention should have been rare.

But there was mistake in the way back-references were handled.

Back-references were done after an Item was merged with the Item in storage. This means that
if a .class file was contained in a lot of different JAR files, each time the .class file was processed,
it updated all the references to all the JAR files that it had previously been referenced.

This was causing lock contention and a lot of extra processing.

This change should speed Goat Rodeo by 2x or more.

📝 Test Plan

Existing tests pass

📜 Documentation

Scala docs

💣 Quality Control

(All items must be checked before a PR is merged)
Did you…

• Mention an issue number in the PR title?
• Update the version # in the build file?
• Create new and/or update relevant existing tests?
• Create or update relevant documentation and/or diagrams?
• Comment your code?
• Fix any stray verbose logging (removing, or moving to debug / trace level)?

Before Merging…

• Make sure the Quality Control boxes are all ticked
• Make sure any open comments or conversations on the PR are resolved