Global MCS tracking example

[w-k-jones]

Example tracking MCSs in global km-scale model data based on the MCSMIP protocol. This example uses remotely accessible ICON model data from MPI

Note: this PR is based on #489 , so should wait until that is merged before merging

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 63.52%. Comparing base (b2d23ff) to head (a5010ca).
⚠️ Report is 68 commits behind head on RC_v1.6.x.

Additional details and impacted files

@@            Coverage Diff             @@
##           RC_v1.6.x     #492   +/-   ##
==========================================
  Coverage      63.52%   63.52%           
==========================================
  Files             27       27           
  Lines           3836     3836           
==========================================
  Hits            2437     2437           
  Misses          1399     1399           

Flag	Coverage Δ
unittests	63.52% <ø> (ø)

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[github-actions]

Linting results by Pylint:

Your code has been rated at 8.21/10 (previous run: 8.21/10, +0.00)
_{The linting score is an indicator that reflects how well your code version follows Pylint’s coding standards and quality metrics with respect to the RC_v1.6.0 branch.
A decrease usually indicates your new code does not fully meet style guidelines or has potential errors.}

[w-k-jones]

Changing to ready to review now that v1.6 is released

[freemansw1]

This is an absolutely phenomenal example. Great work, @w-k-jones .

[JuliaKukulies]

Super nice example! I think this one can be merged in our new release candidate, right? @freemansw1 @w-k-jones

[w-k-jones]

Thanks @JuliaKukulies and @freemansw1 , I'll merge into RC_v1.6.x