ui: App tile actions. Change entry points to Activity and Send Push

JIRA: https://issues.jboss.org/browse/AGPUSH-741

- adds app tile icons to apps page and Push Network Details for SimplePush variants on details page.
- removes Send Push button from details page to reduce noise since this feature can now be accessed from the apps page.
- Minor visual tweaks
This change is wrong, it will add change the text to "You have No applications." again