Gray out calib (3/N)

This MR extracts the extrinsic parameters from Control into their own widget ExtrinsicBox.

• Introduces ExtrinsicParameters-Struct
• Extract ExtrinsicBox from Control

Comments on the changes to the ExtrCalibration-tests are welcome. I used the setXml-function to inject parameters, because I did not want to introduce a getExtrinsicBox method in Control. This somehow lowers the ergonomics of the tests. However, I feel like we'd need to first reduce dependencies to be able to do it differently, i.e. use proper Dependency Injection, injecting the ExtrinsicBox directly into ExtrCalibration.

Reviewer Checklist

Formatting

• the pre-build checks succeed

General code quality

• naming conventions are met (see .clang-tidy for detailed information)
• no static analyzer warnings in new code parts (e.g., use clang-tidy for checking)

General usability

• old versions of pet-files are still loadable

Only if changes in UI

• new elements are also saved and loaded from pet-file
• check if tab order is still correct
• all new SpinBoxes are promoted
• new keybindings added to Petrack::keyBindings()