Updating pin-related functionality

[albeanth]

What is the change?

These changes are to support upgrades in pin-related functionality. The changes in this PR can be lumped into the following buckets:

1. History Tracker: "detail assemblies" are now fuel and control assemblies. I also added some type hints to this module to help understand what was getting passed around.
2. Removing blocks.py::Block::breakFuelComponentsIntoIndividuals. This is removed because it is a very memory expensive way of storing pin level characteristics. Storing data as numpy arrays is much more manageable.
3. Move getPuMoles from blocks.py up to composites.py
4. Populate molesHmBOL and puFrac on components during completeInitialLoading.
5. Add a method getPinMgFluxes to retrieve the pin-wise multigroup fluxes from a Block.

Why is the change being made?

To support downstream pin-related functionality upgrades.

close #791

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Checklist

• This PR has only one purpose or idea. Sorry 😞
• Tests have been added/updated to verify any new/changed code.

• The code style follows good practices.
• The commit message(s) follow good practices.

• The release notes have been updated if necessary.
• The documentation is still up-to-date in the doc folder.
• The dependencies are still up-to-date in pyproject.toml.

[albeanth]

@zachmprince a heads up

[john-science]

@albeanth Does this PR require any changes to the ARMI docs?

[albeanth]

As of right now? No, not that I'm aware of.

[john-science]

@zachmprince @albeanth I have bumped ARMI 0.5.0 (release coming soon).

This means that your release notes need to be moved from 0.4.1 in the file doc/release/0.4.rst to 0.5.0 in the file doc/release/0.5.rst.

Sorry to bother. I would have done this for you, but your PR is coming from a forked repo so I can't.

[albeanth]

Sorry to bother. I would have done this for you, but your PR is coming from a forked repo so I can't.

All good. Already managed!

[drewj-tp]

New changes look good. Minor function name change that is non-blocking