feat: introduce listUsers, listPolicies for any bucket (#12372)

Bonus change LDAP settings such as user, group mappings
are now listed as part of `mc admin user list` and
`mc admin group list`

Additionally this PR also deprecates the `/v2` API
that is no longer in use.

pkg/iam/policy/policy.go

@@ -97,6 +97,16 @@ type Policy struct {
 	Statements []Statement `json:"Statement"`
 }
 
+// MatchResource matches resource with match resource patterns
+func (iamp Policy) MatchResource(resource string) bool {
+	for _, statement := range iamp.Statements {
+		if statement.Resources.MatchResource(resource) {
+			return true
+		}
+	}
+	return false
+}
+
 // IsAllowed - checks given policy args is allowed to continue the Rest API.
 func (iamp Policy) IsAllowed(args Args) bool {
 	// Check all deny statements. If any one statement denies, return false.

pkg/iam/policy/resource.go

@@ -48,7 +48,12 @@ func (r Resource) IsValid() bool {
 	return r.Pattern != ""
 }
 
-// Match - matches object name with resource pattern.
+// MatchResource matches object name with resource pattern only.
+func (r Resource) MatchResource(resource string) bool {
+	return r.Match(resource, nil)
+}
+
+// Match - matches object name with resource pattern, including specific conditionals.
 func (r Resource) Match(resource string, conditionValues map[string][]string) bool {
 	pattern := r.Pattern
 	for _, key := range condition.CommonKeys {

pkg/iam/policy/resourceset.go

@@ -99,6 +99,16 @@ func (resourceSet ResourceSet) MarshalJSON() ([]byte, error) {
 	return json.Marshal(resources)
 }
 
+// MatchResource matches object name with resource patterns only.
+func (resourceSet ResourceSet) MatchResource(resource string) bool {
+	for r := range resourceSet {
+		if r.MatchResource(resource) {
+			return true
+		}
+	}
+	return false
+}
+
 // Match - matches object name with anyone of resource pattern in resource set.
 func (resourceSet ResourceSet) Match(resource string, conditionValues map[string][]string) bool {
 	for r := range resourceSet {