Component paste function seems to break if there are no available paste zones

[taylortom]

Expected Behaviour

You should either get some sort of feedback if paste isn't available, or be able to paste a component into a new block (the former is an easier and more logical solution).

Steps to Reproduce

1. Make sure the page you're on has no available component slots
2. Copy any component
3. Notice nothing happens, but you lose all 'add' buttons, so must refresh the page to add new content

[taylortom]

@canstudios-scottd's fix has been ported to the v1.0 code