Update metadata factory with timeouts and docstrings + use timeouts in instrument calibrations

This MR adds support for optional timeouts parameters for the metadata API calls in MetadataFactory. Currently these default to inf which could result in connections hanging indefinitely if certain network issues are present. The lack of timeouts in our instrument calibration metadata calls is suspected to have caused recent failures in our filtering pipeline when the database server was down.

I also took this opportunity to add in docstrings for the methods in metadata-factory and fix the docstrings in InstrumentCalibrations.