Adds a 'State' section with lists of materials

[pipliggins]

Fixes #4
Fixes #89

Adds a 'State' section to the schema as per BPX 1.0. All Initial conditions & Thermal state params are required, while Degradation is optional.

Parameters described in the current BPX schema as 'colon separated' are implemented as follows:

Degradation: {
  "LLI": 5
  "LAM: Positive electrode": {
     "Primary": 10,
     "Secondary": 20
     }
  "LAM: Negative electrode": 15
}

following discussions in #112.

Errors are raised directing users to the new State section where existing parameters have been moved.

I haven't made any currently optional parameters required (see #89 (comment)) as I'm not entirely clear which should be changed.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 97.53086% with 2 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (main@0cf060d). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
bpx/schema_utils.py	95.00%	0 Missing and 2 partials ⚠️

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[pipliggins]

This also adds the required parameters for #60, but doesn't implement the modification of other parameters mentioned.

[pipliggins]

Note - in the V1.0 PDF, both Initial & Ambient temperature are still listed in the Cell portion of Table 1 as well as in Table 2, I assume that's a bug.

[rtimms]

thanks @pipliggins !

@ejfdickinson we will need to update the BPX spec document to reflect these changes