Raise an exception if no 2D murfey ids present

[stephen-riggs]

We keep hitting a case where no ids get sent to 2D classification. It's not clear why this happens, but if we don't have ids to send it would be better to just raise an exception in murfey.

Also I've changed the fixed number of 50 ids to the value in the default parameters (which is also 50 currently).

[codecov]

Codecov Report

❌ Patch coverage is 0% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 35.03%. Comparing base (e4b297a) to head (2e79985).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #683      +/-   ##
==========================================
- Coverage   35.04%   35.03%   -0.02%     
==========================================
  Files          91       91              
  Lines       11122    11126       +4     
  Branches     1479     1481       +2     
==========================================
  Hits         3898     3898              
- Misses       7097     7101       +4     
  Partials      127      127              

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[tieneupin]

Looks good to me! Just one comment about pre-emptively applying the same logic to the 3D class version of this function as well.