fix: Make IDP routes independent of handlers

test/unit/identity/interaction/routing/AbsolutePathInteractionRoute.test.ts

@@ -0,0 +1,12 @@
+import {
+  AbsolutePathInteractionRoute,
+} from '../../../../../src/identity/interaction/routing/AbsolutePathInteractionRoute';
+
+describe('An AbsolutePathInteractionRoute', (): void => {
+  const path = 'http://example.com/idp/path/';
+  const route = new AbsolutePathInteractionRoute(path);
+
+  it('returns the given path.', async(): Promise<void> => {
+    expect(route.getPath()).toBe('http://example.com/idp/path/');
+  });
+});