Data Catalog EntryGroup

[danawillow]

Part of hashicorp/terraform-provider-google#5892.

I'm going to hold off on merging until a few more resources are ready, but breaking up into separate PRs for easier reviewability.

Release Note Template for Downstream PRs (will be copied)

`google_data_catalog_entry_group`

`google_data_catalog_entry_group_iam_member`

`google_data_catalog_entry_group_iam_binding`

`google_data_catalog_entry_group_iam_policy`

[modular-magician]

Hi! I'm the modular magician. Your PR generated some diffs in downstreams - here they are.

Diff report:

Terraform GA: Diff ( 11 files changed, 1282 insertions(+), 3 deletions(-))
Terraform Beta: Diff ( 11 files changed, 1282 insertions(+), 3 deletions(-))
TF Conversion: Diff ( 2 files changed, 67 insertions(+))
TF OiCS: Diff ( 8 files changed, 211 insertions(+))

[danawillow]

FYI import is not so great in this PR but I fixed it in #3532. As long as they're both in the same TPG release, I'm not concerned.

[megan07]

EntryGroup looks good! I will review TagTemplates once it's uncommented - I actually learned a lot from your PR - on things I should be aware of when I'm writing out resources, so wanted to thank you for that too!