add folder_id as output to folder datasource and resource

[megan07]

While reviewing the Cloud Asset Feed resources, we found that folder_id might be a helpful output of google_folder

#3750 (comment)

Release Note Template for Downstream PRs (will be copied)

resourcemanager: added `folder_id` as computed attribute to `google_folder` resource and datasource.

[modular-magician]

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

Diff report:

Terraform GA: Diff ( 4 files changed, 13 insertions(+), 3 deletions(-))
Terraform Beta: Diff ( 4 files changed, 13 insertions(+), 3 deletions(-))

[modular-magician]

I have triggered VCR tests based on this PR's diffs. See the results here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=134586"

[modular-magician]

I have triggered VCR tests in RECORDING mode for the following tests that failed during VCR: TestAccCloudAssetFolderFeed_cloudAssetFolderFeedExample|TestAccCloudAssetOrganizationFeed_cloudAssetOrganizationFeedExample|TestAccCloudAssetProjectFeed_cloudAssetProjectFeedExample|TestAccContainerCluster_withPrivateClusterConfigMissingCidrBlock|TestAccServiceAccountIamMember_withAndWithoutCondition|TestAccServiceAccountIamBinding_withAndWithoutCondition You can view the result here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=134587"