chore: Adds the ability to see the existing filter when we apply a new filter (#6310)

* feat: Adds existing filter to advance filter modal when we apply a filter

app/javascript/shared/mixins/specs/filterMixin.spec.js

@@ -10,4 +10,8 @@ describe('Test mixin function', () => {
   it('should return proper value from bool', () => {
     expect(wrapper.vm.setFilterAttributes).toBeTruthy();
   });
+
+  it('should return proper value from bool', () => {
+    expect(wrapper.vm.initializeExistingFilterToModal).toBeTruthy();
+  });
 });