Support for 'self' facet linking in newrelic_one_dashboard_json

[jsbnr]

Feature Description

Currently you need to provide the dashboard GUID to facet link a widget to the same dashboard. This can only be accomplished via a two stage apply - first creating the dashboard and then updating it with the known GUID.

The other dashboard resources seem to work around this, I suspect via a two stage commit under the hood. I am sure that ideally the graphQL api itself should be offering this functionality, but perhaps the provider could provide a hack until thats available?

Describe Alternatives

Some options:

• Encourage dashboards graphQL API to support this feature
• Allow a "SELF" placehodler to be added to the template which terraform auto-replaces in the background
• Create dashbaord with existing resource and allow newrelic_one_dashboard_json to take a GUID as a parameter and apply updates to that dashboard.

Additional context

This is the JSON widget component where the GUID has to be supplied

"linkedEntityGuids": [
            "GUID-HERE"
 ],