dials.rlv - handle cases where the beam centre cannot be set

[dagewa]

Previously when a beam centre could not be calculated, dials.reciprocal_lattice_viewer would raise errors and may even distort the lattice (see #2481). The distortion was occurring because the beam centre controls defaulted to 0.0, 0.0. In some situations when setting the beam centre failed, the beam centre was then read from the control values and therefore set to 0.0, 0.0.

This PR works around by disabling the controls in situations when the beam centre cannot be set. Then, if the control is disabled, its value will not be passed back when updating the models.

[codecov]

Codecov Report

Merging #2483 (4d07ce7) into main (9e7f4dc) will decrease coverage by 0.04%.
The diff coverage is n/a.

❗ Current head 4d07ce7 differs from pull request most recent head a31d7bd. Consider uploading reports for the commit a31d7bd to get more accurate results

@@            Coverage Diff             @@
##             main    #2483      +/-   ##
==========================================
- Coverage   78.63%   78.60%   -0.04%     
==========================================
  Files         607      607              
  Lines       74365    74365              
  Branches    10121    10121              
==========================================
- Hits        58479    58451      -28     
- Misses      13731    13758      +27     
- Partials     2155     2156       +1     

[biochem-fan]

Thank you very much.

I confirmed that this fixed problems I reported.