Add TRACE, CONNECT, and PATCH http methods (elastic#31035)

This is related to elastic#31017. That issue identified that these three http
methods were treated like GET requests. This commit adds them to
RestRequest. This means that these methods will be handled properly and
generate 405s.

modules/transport-netty4/src/main/java/org/elasticsearch/http/netty4/Netty4HttpRequest.java

@@ -119,7 +119,19 @@ public Method method() {
             return Method.OPTIONS;
         }
 
-        return Method.GET;
+        if (httpMethod == HttpMethod.PATCH) {
+            return Method.PATCH;
+        }
+
+        if (httpMethod == HttpMethod.TRACE) {
+            return Method.TRACE;
+        }
+
+        if (httpMethod == HttpMethod.CONNECT) {
+            return Method.CONNECT;
+        }
+
+        throw new IllegalArgumentException("Unexpected http method: " + httpMethod);
     }
 
     @Override

plugins/transport-nio/src/main/java/org/elasticsearch/http/nio/NioHttpRequest.java

@@ -84,7 +84,19 @@ public Method method() {
             return Method.OPTIONS;
         }
 
-        return Method.GET;
+        if (httpMethod == HttpMethod.PATCH) {
+            return Method.PATCH;
+        }
+
+        if (httpMethod == HttpMethod.TRACE) {
+            return Method.TRACE;
+        }
+
+        if (httpMethod == HttpMethod.CONNECT) {
+            return Method.CONNECT;
+        }
+
+        throw new IllegalArgumentException("Unexpected http method: " + httpMethod);
     }
 
     @Override

server/src/main/java/org/elasticsearch/rest/RestRequest.java

@@ -130,7 +130,7 @@ public RestRequest(
     }
 
     public enum Method {
-        GET, POST, PUT, DELETE, OPTIONS, HEAD
+        GET, POST, PUT, DELETE, OPTIONS, HEAD, PATCH, TRACE, CONNECT
     }
 
     public abstract Method method();