Add Get/Put Bucket Lock Configuration API support (#8120)

This feature implements [PUT Bucket object lock configuration][1] and
[GET Bucket object lock configuration][2]. After object lock
configuration is set, existing and new objects are set to WORM for
specified duration. Currently Governance mode works exactly like
Compliance mode.

Fixes #8101

[1] https://docs.aws.amazon.com/AmazonS3/latest/API/RESTBucketPUTObjectLockConfiguration.html
[2] https://docs.aws.amazon.com/AmazonS3/latest/API/RESTBucketGETObjectLockConfiguration.html

cmd/utils.go

@@ -492,3 +492,11 @@ func getMinioMode() string {
 func iamPolicyName() string {
 	return globalOpenIDConfig.ClaimPrefix + iampolicy.PolicyName
 }
+
+func isWORMEnabled(bucket string) (Retention, bool) {
+	if globalWORMEnabled {
+		return Retention{}, true
+	}
+
+	return globalBucketRetentionConfig.Get(bucket)
+}