Add calibration with RMF file

[matteobachetti]

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 96.42%. Comparing base (e0b10f1) to head (ba6cc47).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #804      +/-   ##
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+ Coverage   96.41%   96.42%   +0.01%     
==========================================
  Files          45       45              
  Lines        8989     9016      +27     
==========================================
+ Hits         8667     8694      +27     
  Misses        322      322              

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[matteobachetti]

@mgullik good catch on the default_nustar_rmf, it was a leftover from HENDRICS' documentation with no real effect. I added the possibility to calibrate directly at read or initialization, I agree it's a simple and very useful addition.

[matteobachetti]

The test rmf file is just taken from an old NuSTAR observation, I don't remember the details 😅