Improve specificity for simulated SMV format readers

[dagewa]

• Removed rather low specificity FormatSMVADSCmlfsom
• Tweaked the base class FormatSMVADSC so that it would now read old MLFSOM images, like the one in dials_regression/image_examples/MLFSOM_simulation/
• Tweaked FormatSMVJHSim so that it would read modern MLFSOM images that have BEAMLINE=FAKE

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 42.20%. Comparing base (78147cc) to head (ba8d890).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #708 +/- ## ========================================== + Coverage 42.15% 42.20% +0.05% ========================================== Files 188 187 -1 Lines 16764 16743 -21 Branches 3196 3191 -5 ========================================== Hits 7067 7067 + Misses 9052 9031 -21 Partials 645 645 ```