fetch all data first and then only update changed objects

[bb-Ricardo]

Is your feature request related to a problem? Please describe.
Currently every object is requested separately to compare the vCenter attributes with NetBox attributes. This is very time consuming.

Describe the solution you'd like
All objects should be queried at the beginning, then compared and only the changed objects should be changed in NetBox.

Currently the Sync takes 1hour and 30 Minutes for each run. This could be reduced to (wild guess) 2 minutes after an initial sync.

[bb-Ricardo]

related to https://github.com/bb-Ricardo/vcenter-netbox-sync/issues/5