Quit agent endpoint with config (#14223)

* Add agent/v1/quit endpoint
  * Closes https://github.com/hashicorp/vault/issues/11089
* Agent quit API behind config setting
* Normalise test config whitespace
* Document config option

Co-authored-by: Rémi Lapeyre <remi.lapeyre@lenstra.fr>
Co-authored-by: Ben Ash <32777270+benashz@users.noreply.github.com>

command/server/config_test_helpers.go

@@ -780,22 +780,25 @@ func testConfig_Sanitized(t *testing.T) {
 func testParseListeners(t *testing.T) {
 	obj, _ := hcl.Parse(strings.TrimSpace(`
 listener "tcp" {
-	address = "127.0.0.1:443"
-	cluster_address = "127.0.0.1:8201"
-	tls_disable = false
-	tls_cert_file = "./certs/server.crt"
-	tls_key_file = "./certs/server.key"
-	tls_client_ca_file = "./certs/rootca.crt"
-	tls_min_version = "tls12"
-	tls_max_version = "tls13"
-	tls_require_and_verify_client_cert = true
-	tls_disable_client_certs = true
-    telemetry {
-      unauthenticated_metrics_access = true
-    }
-    profiling {
-      unauthenticated_pprof_access = true
-    }
+  address = "127.0.0.1:443"
+  cluster_address = "127.0.0.1:8201"
+  tls_disable = false
+  tls_cert_file = "./certs/server.crt"
+  tls_key_file = "./certs/server.key"
+  tls_client_ca_file = "./certs/rootca.crt"
+  tls_min_version = "tls12"
+  tls_max_version = "tls13"
+  tls_require_and_verify_client_cert = true
+  tls_disable_client_certs = true
+  telemetry {
+    unauthenticated_metrics_access = true
+  }
+  profiling {
+    unauthenticated_pprof_access = true
+  }
+  agent_api {
+    enable_quit = true
+  }
 }`))
 
 	config := Config{
@@ -833,6 +836,9 @@ listener "tcp" {
 					Profiling: configutil.ListenerProfiling{
 						UnauthenticatedPProfAccess: true,
 					},
+					AgentAPI: &configutil.AgentAPI{
+						EnableQuit: true,
+					},
 					CustomResponseHeaders: DefaultCustomHeaders,
 				},
 			},