Add CallbackMovie (#1544)
Add CallbackMovie (#1544)

* Added CallbackMovie

Code for #1135

* PEP8 and docstring test

I don't quite know how to properly handle the docstring tests. Any ideas?

* Maybe Fix of docstring test

* Let's try this one more time...

* Intercepted/Clarified Errors thrown for the users

Errors have meaningfull messages
Added __repr__, but need help with parameters that are consumed by Matplotlib.animation
Changed codec in docstring, so maybe pytest can cope with this one

* Implemented contextmanager as suggested by @kohr-h

* nonlocal im no longer overwritten

* Fixed some docstrings and extracted plot_in_figure to seperate method

* Complete and fix some docs

* Apply suggestions from code review

* Several fixes in save_animation

- Use first available writer by default instead of fixed one
- Use figure DPI by default, otherwise create figure with given DPI
- Documentation fixes, mostly by linking to MPL docs
- Simplify implementation of CallbackAppendFrame

Closes: #1135 

Co-authored-by: Holger Kohr <14fa818e44c52c1ccc5280787049f71f083ffdd7@zoho.com>
kohr-h/odl,odlgroup/odl,kohr-h/odl,odlgroup/odl