Add `RedSol` modeling functionality, begin reorganization of redcal.py

[jsdillon]

This PR builds on @AaronParsons's first pass in f8652c6f50dd8ff1d78c9d88789cbec942b01291 to add modeling functionality to the RedSol object. It also:

• Moves remove_degen_gains to the top level of redcal.py, whichRedSol.remove_degen` calls.
• Makes RedundantCalibrator.remove_degen_gains call remove_degen_gains under the hood.
• Makes RedundantCalibrator.remove_degen call RedSol.remove_degen under the hood.
• Avoids the creation of unnecessary arrays in utils.chisq
• Avoids unnecessary copying in logcal
• Updates unit tests as appropriate.

[codecov[bot]]

Codecov Report

Base: 97.33% // Head: 97.34% // Increases project coverage by +0.01% :tada:

Coverage data is based on head (9aa9261) compared to base (127513d). Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #838 +/- ## ========================================== + Coverage 97.33% 97.34% +0.01% ========================================== Files 17 17 Lines 8254 8250 -4 ========================================== - Hits 8034 8031 -3 + Misses 220 219 -1 ``` | [Impacted Files](https://codecov.io/gh/HERA-Team/hera_cal/pull/838?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=HERA-Team) | Coverage Δ | | |---|---|---| | [hera\_cal/redcal.py](https://codecov.io/gh/HERA-Team/hera_cal/pull/838/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=HERA-Team#diff-aGVyYV9jYWwvcmVkY2FsLnB5) | `99.21% <100.00%> (+0.09%)` | :arrow_up: | | [hera\_cal/utils.py](https://codecov.io/gh/HERA-Team/hera_cal/pull/838/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=HERA-Team#diff-aGVyYV9jYWwvdXRpbHMucHk=) | `96.25% <100.00%> (+0.01%)` | :arrow_up: | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=HERA-Team). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=HERA-Team)

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