Remove redundant mongo

[yuema137]

Fix #136
The classes are redefined in straxen: straxen/storange/mongo_storage.py and all of the other xenon packages are only using the implementation in straxen (See #136 ). Given the independence of this module, it doesn't really matter if it's implemented in straxen or utilix. To avoid potential ambiguity in the future, a good practice is to remove the implementation here.

I have checked that the mongo_files module is independent of other modules in utilix, and it's safe to remove it.

[dachengx]

APIUploader and APIDownloader are still used: https://github.com/XENONnT/private_nt_aux_files/blob/4b155401e986b3c33a37b687c27d12c757763c27/ntauxfiles/uploader.py#L12

[yuema137]

@dachengx Please see the straxen PR: XENONnT/straxen#1442
and the private_nt_aux_files PR: https://github.com/XENONnT/private_nt_aux_files/pull/387

[dachengx]

@dachengx Please see the straxen PR: XENONnT/straxen#1442 and the private_nt_aux_files PR: XENONnT/private_nt_aux_files#387

You need to solve the conflicts with the master branch.

[dachengx]

Actually, haha, I suggest keeping these things to utilix but not straxen, because straxen is too heavy, and import straxen takes more resources.

[dachengx]

Thanks @yuema137 Please later move RunDB related classes from straxen to utilix.

[yuema137]

@dachengx Yes let's first gather the functions into one file in straxen, then move it to utilix. Then there's no need to modify private_nt_aux_files