Merge fetch_nwb errors

[edeno]

Describe the bug
Merge fetch_nwb does not work. Results in a property error.

The culprit is PR #730
When I reverted this line:

spyglass/src/spyglass/utils/dj_merge_tables.py

Line 516 in daf671e

(cls.analysis_nwbfile, "analysis_file_abs_path"),

from cls.analysis_nwbfile to AnalysisNwbfile it worked again.

To Reproduce
Steps to reproduce the behavior:
Run fetch_nwb on a merge table

[CBroz1]

The property is needed to avoid circular import on startup, but it needs to be run on the class instance, not the class itself

(cls.analysis_nwbfile, "analysis_file_abs_path"), -> (cls().analysis_nwbfile, "analysis_file_abs_path"),