Extend TimeSeries.resample() to support more resampling methods

[jonasblanc]

Checklist before merging this PR:

• Mentioned all issues that this PR fixes or addresses.
• Summarized the updates of this PR under Summary.
• Added an entry under Unreleased in the Changelog.

Fixes #699

Summary

• Expose all aggregation functions of xarray.DataArrayResample through the "method" argument of TimeSeries.resample().
• Let users specify method specific arguments through method_args.
• Extend tests with at least one test per additional method.

Other Information

• Not all methods make sense for either down/up-sampling. I chose not to restrict the use of such methods in situation where they are not expected to be used (ie. xarray is responsible for handling such case). However while testing I encountered this bug: issue xarray asfreq which happens when asfreq is used for down-sampling.
• I chose to give access to any() and all() aggregation methods, to be consistent with TimeSeries, I cast bool back to int after the aggregation.
• I chose to let pad as the default method so as not to break the default behavior, even though it's not the most intuitive method for down-sampling.

[madtoinou]

Nice contribution @jonasblanc, some minor comments to improve the readibility

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.17%. Comparing base (c52ec83) to head (c16d0dd).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2643      +/-   ##
==========================================
- Coverage   94.20%   94.17%   -0.04%     
==========================================
  Files         141      141              
  Lines       15491    15493       +2     
==========================================
- Hits        14594    14591       -3     
- Misses        897      902       +5     

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[dennisbader]

Very nice PR, thanks and great job @jonasblanc 🚀 Just had some minor suggestions, after that we're ready to merge :)

[madtoinou]

LGTM, great first contribution @jonasblanc! 🚀