New channel dialog should focus the 'name' field

The 'name' field of the new channel dialog should be focused automatically, so the user can start typing the name right away.

Steps to reproduce:
1. go to the channel overview in the CMS
2. click 'Add channel'
3. select a blueprint and click 'Next'

Expected: the 'name' field is focused and has a cursor, so you can directly type in the name of a new channel
Actual: no field is focused; you have to click on the 'name' field first before you're able to enter a name