Fix run caly model devi

[wangzyphysics]

CALYPSO will propose structures with different chemical formula when using VSC mode. However, dpdata cannot parse a dump file containing frames with different chemical formula. To resolve this issue, frames are separated into different dump files based on the number of atoms in each frame.

[codecov]

Codecov Report

Attention: Patch coverage is 39.21569% with 31 lines in your changes are missing coverage. Please review.

Project coverage is 86.56%. Comparing base (00d3f5e) to head (aa6780b).

Files	Patch %	Lines
dpgen2/op/run_caly_model_devi.py	11.76%	30 Missing ⚠️
dpgen2/op/collect_run_caly.py	94.11%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #197      +/-   ##
==========================================
- Coverage   86.85%   86.56%   -0.30%     
==========================================
  Files          92       92              
  Lines        4764     4794      +30     
==========================================
+ Hits         4138     4150      +12     
- Misses        626      644      +18     

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