DEV: Add Notebook AST Pre-Commit Hook

[John-P]

Add a simple pre-commit check which iterates over code cells in each notebook file and checks that any lines which don't start with a ! are valid python, i.e. that they parse to an abstract syntax tree (AST).

This PR also removes a broken and unused old hook.

[codecov]

Codecov Report

Merging #417 (84f5102) into develop (8705422) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop     #417   +/-   ##
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  Coverage    99.60%   99.60%           
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  Files           55       55           
  Lines         5367     5367           
  Branches       962      962           
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  Hits          5346     5346           
  Misses           9        9           
  Partials        12       12