Keyboard accessibility for emoji picker and profile tabs

[juliushaertl]

Fixes #96

[jancborchardt]

Awesome, thank you! :) Only one thing: Is it possible that after pressing enter on the emoji picker toggle, the input field is automatically focused so you can start typing?

[juliushaertl]

@jancborchardt Fixed as well.

[jancborchardt]

And sorry – two other things with the flow:

• When you type in the search field and then press enter, the first emoji should automatically be inserted. (Currently you need to tab and then press enter.)
• After inserting an emoji like this, the picker should automatically be closed with a space inserted after it so you can continue typing.

Is that possible? This will be very useful for everyone using the emoji picker. :)

[juliushaertl]

@jancborchardt I'd just look into this two issues in a separate PR, since they will require a bit more work.