Update hooks for version 11

[dcode]

I know version 11 is obviously not officially released, but the testing builds are quite good. Seemingly the hook changed, or the DOM path, but the import button no longer renders. It might be nice to put the button in the top group.

Current rendering:

Proposed rendering:

HTML at selector path #scenes > header > div.header-actions.action-buttons.flexrow > button.import-uvtt

<button class="import-uvtt"><i class="fas fa-file-import"></i> Universal Battlemap Import</button>