Allow users to pass inner to sc.pl.violin when multi_panel=True

[ivirshup]

Might fix my proposed solution for #2051

@WeilerP, do you remember why you explicitly set inner=None here in #1422?

[codecov]

Codecov Report

Merging #2083 (da2d5dd) into master (58f4904) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2083      +/-   ##
==========================================
- Coverage   71.21%   71.20%   -0.02%     
==========================================
  Files          92       92              
  Lines       11248    11250       +2     
==========================================
  Hits         8010     8010              
- Misses       3238     3240       +2     

Impacted Files	Coverage Δ
scanpy/plotting/_anndata.py	85.34% <ø> (ø)
scanpy/tools/_louvain.py	20.21% <0.00%> (-0.44%)	⬇️

[WeilerP]

Hm, no, sorry not entirely sure. I guess it was to mimic the behavior here. In the original implementation, kwds wasn't passed to the stripplot function (see here) but it was in #1422. From briefly skimming the docs here I believe inner and cut aren't valid arguments.