feat: add additional supported interfaces

This includes the relevant auth headers and a simplification of several others.

src/ldp/http/Patch.ts

@@ -1,4 +1,6 @@
+import { Representation } from './Representation';
+
 /**
  * Represents the changes needed for a PATCH request.
  */
-export interface Patch {}
+export interface Patch extends Representation {}

src/ldp/http/RequestParser.ts

@@ -0,0 +1,8 @@
+import { AsyncHandler } from '../../util/AsyncHandler';
+import { HttpRequest } from '../../server/HttpRequest';
+import { Operation } from '../operations/Operation';
+
+/**
+ * Converts an incoming HttpRequest to an Operation.
+ */
+export type RequestParser = AsyncHandler<HttpRequest, Operation>;