Add test to button favorite

$ yarn run start:storybook:test

Test for the following
- Material id is not on user's favorites list
- Material id is on user's favorites list
- User can add and remove material id from favorite list

src/components/button-favourite/button-favourite.test.ts

@@ -0,0 +1,46 @@
+describe("Favorite button", () => {
+  it("Material id is not on user's favorites list", () => {
+    cy.intercept("HEAD", "**/list/default/**", {
+      statusCode: 404,
+      body: {}
+    });
+    cy.visit(
+      "/iframe.html?args=&id=components-button-favourite--favourite&viewMode=story"
+    );
+    cy.get('[aria-label="Tilføj til favoritter"]');
+  });
+
+  it("Material id is on user's favorites list", () => {
+    cy.intercept("HEAD", "**/list/default/**", {
+      statusCode: 200,
+      body: {}
+    });
+    cy.visit(
+      "/iframe.html?args=&id=components-button-favourite--favourite&viewMode=story"
+    );
+    cy.get('[aria-label="Fjern fra favoritter"]');
+  });
+
+  it("User can add and remove material id from favorite list", () => {
+    cy.intercept("HEAD", "**/list/default/**", {
+      statusCode: 404,
+      body: {}
+    });
+    cy.intercept("PUT", "**/list/default/**", {
+      statusCode: 201,
+      body: {}
+    });
+    cy.intercept("DELETE", "**/list/default/**", {
+      statusCode: 204,
+      body: {}
+    });
+    cy.visit(
+      "/iframe.html?args=&id=components-button-favourite--favourite&viewMode=story"
+    );
+    cy.get('[aria-label="Tilføj til favoritter"]').click();
+    cy.get('[aria-label="Fjern fra favoritter"]').click();
+    cy.get('[aria-label="Tilføj til favoritter"]').click();
+  });
+});
+
+export {};