Allow saving of CODA plots

[namsaraeva]

First try to harmonise plotting functions in the sccoda module. Will close issue #557

Added save, show and ax parameters to most of the functions.

Also fixed some warnings that occured while testing.

[Zethson]

https://results.pre-commit.ci/run/github/379626476/1710773802.1nc54vF-T_6yiWBrn74N5A

These require manual fixing!

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 63.40%. Comparing base (916c837) to head (ad1c448). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #559 +/- ## ======================================= Coverage 63.40% 63.40% ======================================= Files 43 43 Lines 5052 5052 ======================================= Hits 3203 3203 Misses 1849 1849 ``` | [Files](https://app.codecov.io/gh/theislab/pertpy/pull/559?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=theislab) | Coverage Δ | | |---|---|---| | [pertpy/plot/\_coda.py](https://app.codecov.io/gh/theislab/pertpy/pull/559?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=theislab#diff-cGVydHB5L3Bsb3QvX2NvZGEucHk=) | `100.00% <ø> (ø)` | | | [pertpy/tools/\_coda/\_base\_coda.py](https://app.codecov.io/gh/theislab/pertpy/pull/559?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=theislab#diff-cGVydHB5L3Rvb2xzL19jb2RhL19iYXNlX2NvZGEucHk=) | `56.27% <ø> (ø)` | |