Image render param refactor

[melonora]

This PR refactors the way the parameters for image rendering get validated and passed. Some of the changes are not backward compatible. For element the user can't pass on a list of str anymore, but only str or None. All the passed on parameters are used to create a view config for a single element. If element is None then all the parameters are checked for whether they are valid for a specific element and if that is not the case the value of the parameter for that element is set to None. If a user wants to plot multiple specific images, the pl.render calls can be chained.

Because of creating viewconfigs in such a way that each element has its own contained config this will make it easy to hook up vega like specifications and also to write those out.

[melonora]

ok couple of things that "fail":
This PR versus reference:


Again this PR versus reference:

The remainder of the tests were thinking at least locally for me also on main. @timtreis what is the current status of #262? I would have to merge that one in here, but right now I have no permission to actually checkout that PR with the github cli.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 86.48649% with 30 lines in your changes are missing coverage. Please review.

Project coverage is 77.17%. Comparing base (3ab41eb) to head (8eaf6f4).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #267      +/-   ##
==========================================
- Coverage   77.70%   77.17%   -0.53%     
==========================================
  Files          11       12       +1     
  Lines        1722     1827     +105     
==========================================
+ Hits         1338     1410      +72     
- Misses        384      417      +33     

Files	Coverage Δ
src/spatialdata_plot/pl/basic.py	91.57% <100.00%> (+0.18%)	⬆️
src/spatialdata_plot/pl/render_params.py	100.00% <100.00%> (ø)
src/spatialdata_plot/_utils.py	95.45% <95.45%> (ø)
src/spatialdata_plot/pl/render.py	94.26% <91.17%> (-0.36%)	⬇️
src/spatialdata_plot/pl/utils.py	66.66% <80.83%> (-0.04%)	⬇️

[timtreis]

Only known-to-fail tests fail. We'll fix in main after this refactor