Resolve "Allow plot functions to dynamically enter or leave animation mode"

This MR addresses #140 (closed) and implements the possibility for ExternalPlotCreator plot functions to dynamically enter or exit animation mode.

Details

• PlotHelper is now aware of whether animation mode is enabled or not
• New custom exception types: EnterAnimationMode, ExitAnimationMode (purely for control flow purposes, instead of return values)
• New PlotHelper methods: enable_animation and disable_animation
  • If invoked in a state where a animation mode change is required, they raise one of the above exception
• ExternalPlotCreator catches them, adapts animation parameters and then invokes plotting again
• Error messages are given upon:
  • Missing animation parameters but enable_animation being invoked
  • Repeatedly switching animation modes

Anything to double-check?

• Error messages ok?
• Ideas for other things to test?
• Documentation ok?

Can this MR be accepted?

• Implementation ready
• Tests added or adjusted
• Documentation extended or updated

• Code quality
  • Changes follow coding guidelines
  • Checked code coverage on new and adjusted code

• Ready for merging
  • Pipeline passes without warnings
  • History cleaned-up or squash option set
  • Changelog entry added
  • Version number bumped
  • Reviewed & approved by @herdeanu

Related issues

Closes #140 (closed)