Mask off-detector slits/orders

[debora-pe]

This PR adds the option to mask the portion of a slit/order that is more than 50% outside the detector. This is done, simply, by changing the values of specmin and specmax during slit tracing. This approach allows to avoid funny behaviors during the object extraction where the portion of the slit/order that is on the detector becomes smaller and smaller.

This masking is not done by default but a new parameter mask_off_detector has been introduced and it is set to True by default only for keck_hires.

Tests already run and pass. One unit test failure is my machine usual problem with setup_gui.
FAILED ../../../Pypeit/PypeIt-development-suite/unit_tests/test_setup_gui.py::test_pypeit_obslog_model - PermissionError: [Errno 1] Operation not permitted: '/private/var/folders/x...

Test Summary
--------------------------------------------------------
--- PYTEST PYPEIT UNIT TESTS PASSED  259 passed, 66 warnings in 378.61s (0:06:18) ---
--- PYTEST UNIT TESTS FAILED  1 failed, 151 passed, 168 warnings in 2057.03s (0:34:17) ---
--- PYTEST VET TESTS PASSED  66 passed, 124 warnings in 5591.32s (1:33:11) ---
--- PYPEIT DEVELOPMENT SUITE PASSED 250/250 TESTS  ---
Testing Started at 2025-02-04T17:08:54.523226
Testing Completed at 2025-02-05T11:08:37.776061
Total Time: 17:59:43.252835