Group data lookup by name doesn't respect verified field

[wlynch]

Data lookups by name should only consider groups where verified = true.

Currently, we return the List request back verbatim, without checking verified - This means that we can error if multiple groups happen to have the same name, even though only one can be verified.

│ Error: more than one group found matching input
│ 
│   with data.chainguard_group.enterprise-presubmit,
│   on chainguard.tf line 5, in data "chainguard_group" "enterprise-presubmit":
│    5: data "chainguard_group" "enterprise-presubmit" {
│ 
│ Input parameters: [id=<null>, name="enterprise-presubmit", parent_id=<null>]
│ Please provide more context to narrow query (e.g. parent_id).

We should probably default to only checking verified names, maybe with a flag to relax the constraint.