AppList: Add hover state on create app button

[sohel-rp]

1. Open Create app dropdown on hovering on [+Create App] button instead of clicking on it
2. User should be able to click on items in the dropdown
3. Dropdown should not close unless the cursor/pointer moves out of the button or dropdown area
4. Dropdown should not open/close on the [+Create App] button click

AB#428