T279 planar illumination geometry

[RecurvedBow]

Please check the following before creating the pull request (PR):

• [x] Did you run automatic tests?
• [ ] Did you run manual tests?
• [x] Is the code provided in the PR still backwards compatible to previous SIMPA versions?

List any specific code review questions

List any special testing requirements

Additional context (e.g. papers, documentation, blog posts, ...) Since the pull request only includes new files and a single change in an automatic test, existing source code files are not modified and therefore executing manual tests is not required.

Provide issue / feature request fixed by this PR

Fixes #279