feat: add management for ldap idp template (#5220)

Add management functionality for LDAP idps with templates and the basic functionality for the LDAP provider, which can then be used with a separate login page in the future.

---------

Co-authored-by: Livio Spring <livio.a@gmail.com>

internal/domain/idp.go

@@ -0,0 +1,36 @@
+package domain
+
+type IDPState int32
+
+const (
+	IDPStateUnspecified IDPState = iota
+	IDPStateActive
+	IDPStateInactive
+	IDPStateRemoved
+
+	idpStateCount
+)
+
+func (s IDPState) Valid() bool {
+	return s >= 0 && s < idpStateCount
+}
+
+func (s IDPState) Exists() bool {
+	return s != IDPStateUnspecified && s != IDPStateRemoved
+}
+
+type IDPType int32
+
+const (
+	IDPTypeUnspecified IDPType = iota
+	IDPTypeOIDC
+	IDPTypeJWT
+	IDPTypeOAuth
+	IDPTypeLDAP
+	IDPTypeAzureAD
+	IDPTypeGitHub
+	IDPTypeGitHubEE
+	IDPTypeGitLab
+	IDPTypeGitLabSelfHosted
+	IDPTypeGoogle
+)