Add type checking for parameters of bias correction techniques

[btschwertfeger]

Since I got to many E-Mails about "this does not work" and "how should the data look like" I decided to add some TypeErrors to notify users that they need to have lists or xarray.**.DataArrays for some input data.

[codecov]

Codecov Report

Merging #43 (009f292) into master (cca3ead) will decrease coverage by 0.15%.
The diff coverage is 92.85%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #43      +/-   ##
==========================================
- Coverage   98.38%   98.23%   -0.15%     
==========================================
  Files           1        1              
  Lines         247      283      +36     
==========================================
+ Hits          243      278      +35     
- Misses          4        5       +1     

Flag	Coverage Δ
unittests	98.23% <92.85%> (-0.15%)	⬇️

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Files Changed	Coverage Δ
cmethods/__init__.py	98.23% <92.85%> (-0.15%)	⬇️