refactor(ops/keycloak): Split out clients & user-sources

Without some kind of physical organisation it's a little difficult to
understand whether things are going "in" (supplying users to Keycloak)
or "out" (getting auth/user info from Keycloak).

Change-Id: I516501081e3448c81c710fcbc79cc68ad2a80f3b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/4762
Tested-by: BuildkiteCI
Reviewed-by: Profpatsch <mail@profpatsch.de>

ops/keycloak/user_sources.tf

@@ -0,0 +1,21 @@
+# All user sources, that is services from which Keycloak gets user
+# information (either by accessing a system like LDAP or integration
+# through protocols like OIDC).
+
+resource "keycloak_ldap_user_federation" "tvl_ldap" {
+  name                    = "tvl-ldap"
+  realm_id                = keycloak_realm.tvl.id
+  enabled                 = true
+  connection_url          = "ldap://localhost"
+  users_dn                = "ou=users,dc=tvl,dc=fyi"
+  username_ldap_attribute = "cn"
+  uuid_ldap_attribute     = "cn"
+  rdn_ldap_attribute      = "cn"
+  full_sync_period        = 86400
+  trust_email             = true
+
+  user_object_classes = [
+    "inetOrgPerson",
+    "organizationalPerson",
+  ]
+}