fix: Separate toasts storage to own MobX store (#2339)

Co-authored-by: Tom Moor <tom.moor@gmail.com>

app/stores/ToastsStore.test.js

@@ -0,0 +1,28 @@
+/* eslint-disable */
+import stores from '.';
+
+// Actions
+describe('ToastsStore', () => {
+  let store;
+
+  beforeEach(() => {
+    store = stores.toasts;
+  });
+
+  test('#add should add messages', () => {
+    expect(store.orderedData.length).toBe(0);
+    store.showToast('first error');
+    store.showToast('second error');
+    expect(store.orderedData.length).toBe(2);
+  });
+
+  test('#remove should remove messages', () => {
+    store.toasts.clear();
+    const id = store.showToast('first error');
+    store.showToast('second error');
+    expect(store.orderedData.length).toBe(2);
+    store.hideToast(id);
+    expect(store.orderedData.length).toBe(1);
+    expect(store.orderedData[0].message).toBe('second error');
+  });
+});