[feature] Add in missing collectors to guaccollect

[pxp928]

Is your feature request related to a problem? Please describe.
Add in the missing collectors to guaccollect. Currently, GCS, S3, and git are missing. This would allow them to be used via guacingest with pubsub and blob store.

The implementation for these will be very similar to guaccollect files.

GCS and S3 are implemented in guacone so that can be used as a reference.

NOTE:

The documentation (https://docs.guac.sh/) needs to be updated on how to properly set up and utilize guaccollect

[pxp928]

cc @kanchan-dhamane

[nathannaveen]

Could I work on this?

[pxp928]

The documentation (https://docs.guac.sh/) needs to be updated on how to properly set up and utilize guaccollect

[pxp928]

Closing this issue as the work is done. Adding documentation issue guacsec/guac-docs#120