fix: use modal instead of menu inside of a split pane

Closes #234

frontend/app/cypress/integration/context-menu.spec.ts

@@ -14,6 +14,8 @@
  */
 
 describe('context menu', function () {
+  const contextMenuSelector = 'stapps-context-menu-modal';
+
   beforeEach(function () {
     cy.interceptSearch({
       extends: {query: 'a'},
@@ -33,21 +35,21 @@ describe('context menu', function () {
   });
 
   it('should sort', function () {
-    cy.get('stapps-context').within(() => {
+    cy.get(contextMenuSelector).within(() => {
       cy.contains('ion-item', 'Name').click();
       cy.wait('@search');
     });
   });
 
   it('should filter', function () {
-    cy.get('stapps-context').within(() => {
+    cy.get(contextMenuSelector).within(() => {
       cy.contains('ion-item', '(17) Akademische Veranstaltung').click();
       cy.wait('@search');
     });
   });
 
   it('should have a working delete button', function () {
-    cy.get('stapps-context').within(() => {
+    cy.get(contextMenuSelector).within(() => {
       cy.contains('ion-item', '(17) Akademische Veranstaltung').click();
 
       cy.get('.checkbox-checked').should('have.length', 1);
@@ -60,7 +62,7 @@ describe('context menu', function () {
   it('should truncate long category items', function () {
     cy.contains('ion-list', 'Akademische Veranstaltung / Kategorien').within(() => {
       cy.contains('ion-item', '(1) Tutorium').should('not.exist');
-      cy.get('div > ion-button').click();
+      cy.get('ion-button').click();
       cy.contains('ion-item', '(1) Tutorium').should('exist');
     });
   });