Move OPA Gatekeeper guac provider to guacsec org

[pxp928]

Is your feature request related to a problem? Please describe. Currently the OPA gatekeeper guac provider is located at: https://github.com/dejanb/guac-provider

The repo needs to be cleaned up and moved under the guacsec organization.

This will also require the changes from https://github.com/guacsec/guac/compare/main...pxp928:artifact-ff:issue-1734

to be merged into GUAC to allow for the guac-provider to query guac for values via the REST API

[pxp928]

cc @dejanb