Allow for ignoring a UID embedded in a dashboard or datasource

[tculp]

Is your feature request related to a problem? Please describe.
I am unable to add multiple copies of a dashboard using the grafanaCom method, as the dashboard in question has a uid embedded in the json. For example: https://grafana.com/grafana/dashboards/12776-redis/

(If applicable)If your feature request solves a bug please provide a link to the community issue
#1499

Describe the solution you'd like
I would like to be able to provide an alternate UID in the GrafanaDashboard resource, or have a flag to force a new random UID to be generated.

Describe alternatives you've considered
Manually download the json and use the configmap method

[tculp]

Potential defaults that would use the embedded uid (current behavior):

uid: ""
generateUid: false

[theSuess]

We discussed this issue and the way we'd like to solve it is by implementing #1636 for Dashboards. That way, the spec.uid field of the dashboard will always be the UID communicated to Grafana, regardless of the underlying JSON spec.

Keeping this issue open to make sure this use case is covered when implementing the functionality