Print helpful error message in dials.slice_sequence in case of invalid input.

[jbeilstenedmands]

Also allow multi-expt files for exclude_images_multiple

FIxes #2098

[jbeilstenedmands]

In an example case, it now prints:

$ dials.slice_sequence split_0.* image_range=1,20 image_range=25,40
The following parameters have been modified:

image_range = 1 20
image_range = 25 40
input {
  experiments = split_0.expt
  reflections = split_0.refl
}

Sorry: The input experiment list and image_ranges are not of the same length (1 != 2).
To achieve multiple slices from a single sweep, the dials.slice_sequence can be run multiple times with different image_range values.
Alternatively, multi-experiment file pairs can be split with dials.split_experiments to help manage multiple-experiment workflows.

I also found the traceback could be triggered in the new exclude_images_multiple for multi-experiment input, but that case can be handled so the code has been updated.

[dagewa]

Happy that this avoids the user seeing a traceback and the error message provided is informative 👍

[codecov]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (7b19b5f) 78.53% compared to head (6c182e3) 78.54%.

Additional details and impacted files

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##             main    #2570   +/-   ##
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  Coverage   78.53%   78.54%           
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  Files         609      609           
  Lines       75054    75057    +3     
  Branches    10712    10713    +1     
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+ Hits        58945    58951    +6     
+ Misses      13943    13939    -4     
- Partials     2166     2167    +1