Implement Editor Action for Location search input

When the search key on the soft keyboard is hit, we should start the
search. Also show and hide the keyboard when edit is requested and
search is triggered.
Remove "View Map" and make the Location clickable

Simplifies things a bit by removing clutter from the Post Settings
screen.
Add icon to "Add Location" button

Add a cue that the button is for geotagging

h/t joen for the icon