User feedback about the re-index starting

As an Admin I'd like to have a visual feedback after I press Re-Index of JCommune so that I can figure out whether it was successful or not

Acceptance Criteria:

• If an HTTP request was sent to JCommune successfully, then a green popup hint should show up saying 'Re-Indexing was successfully started'.
• If it wasn't possible to find a property that contains JCommune URL, then an error should show up stating something like: 'The component URL Address wasn't specified in the configuration of JCommune. Please go to configuration of the component and specify it'
• If URL was found in properties but the host didn't respond (connection error), then something like 'Could not connect to JCommune, either application is down or incorrect URL was specified in configuration'.
• If URL of JCommune was found and an HTTP error appeared while sending the request, then an error should show up stating something like: 'An error appeared while sending a Re-Indexing request to JCommune. Looks like JCommune URL Address was configured badly'. It also should contain an HTTP error code we got.