Fixes issues with close event not firing when the search term doesn't match and ui closes

[sandeepsuvit]

Thanks a lot for creating this awesome library.

This PR fixes the close event not triggering when the ui closes when the search term doesn't match

Here is the link to the issue that was reproduced https://stackblitz.com/edit/angular-mentions-gww2i3

1. Close event fired when search term match is clicked and ui closes

2. Close event not firing when search term doesn't match but the ui closes

The application I am building requires the close event to be handled by the parent component to set certain properties on the parent component. In the above scenario I am unable to get the close event when the search term doesn't match and the ui closes.

I have added the fix for it in the current PR. Kindly review and merge and share the updated version of the library.