Issue 1405 xaverage

[valentinsulzer]

Description

Reformats the degradation models so that the x-averaged form can be used
Adds a reaction-driven LAM model from Reniers 2019

Fixes #1405

Type of change

Please add a line in the relevant section of CHANGELOG.md to document the change (include PR #) - note reverse order of PR #s. If necessary, also add to the list of breaking changes.

• New feature (non-breaking change which adds functionality)
• Optimization (back-end change that speeds up the code)
• Bug fix (non-breaking change which fixes an issue)

Key checklist:

• No style issues: $ flake8
• All tests pass: $ python run-tests.py --unit
• The documentation builds: $ cd docs and then $ make clean; make html

You can run all three at once, using $ python run-tests.py --quick.

Further checks:

• Code is commented, particularly in hard-to-understand areas
• Tests added that prove fix is effective or that feature works

[codecov]

Codecov Report

Merging #1490 (6835652) into develop (8445c27) will increase coverage by 0.00%.
The diff coverage is 99.75%.

@@           Coverage Diff            @@
##           develop    #1490   +/-   ##
========================================
  Coverage    98.31%   98.32%           
========================================
  Files          295      294    -1     
  Lines        16783    16854   +71     
========================================
+ Hits         16500    16571   +71     
  Misses         283      283           

Impacted Files	Coverage Δ
...s/full_battery_models/lithium_ion/newman_tobias.py	100.00% <ø> (ø)
...ubmodels/interface/lithium_plating/base_plating.py	100.00% <ø> (ø)
...dels/full_battery_models/lead_acid/higher_order.py	98.11% <50.00%> (ø)
pybamm/__init__.py	94.95% <100.00%> (ø)
pybamm/models/base_model.py	99.21% <100.00%> (ø)
...m/models/full_battery_models/base_battery_model.py	99.68% <100.00%> (+0.01%)	⬆️
...ybamm/models/full_battery_models/lead_acid/full.py	100.00% <100.00%> (ø)
...ybamm/models/full_battery_models/lead_acid/loqs.py	100.00% <100.00%> (ø)
...ttery_models/lithium_ion/base_lithium_ion_model.py	100.00% <100.00%> (ø)
...bamm/models/full_battery_models/lithium_ion/dfn.py	100.00% <100.00%> (ø)
... and 23 more

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[rtimms]

neat! thanks, @tinosulzer !

[rtimms]

might be worth a comment here explaining why x_average is True/False for different models (just in dfn, spm etc., not in every submodel)

[rtimms]

very minor style point, but odd for this to be capitalized. I guess to distinguish from self.domain