'add to list' clean up, ux improvements

[markdavella]

• Removed mobile overflow issue with 'create new list' button
• Added auto focus to input after clicking 'create new list'
• Hide 'Create new list' button on mobile after clicking, giving space to just display new input field
• Updated title to better reflect what was happening and to match original button text description of "add" vs "track"

Desktop:

Mobile:

Create new list mobile:

Fixes: https://github.com/chrisbenincasa/teletracker/issues/813