Adding emoji to message: focus in the filter box and make escape work

[wiebeytec]

Description:

After clicking on the 'add emoji' icon for a message, there are two problems:

• if you want to filter, you first have to click the filter box. The way it is now, the popup is half-way pop-up, half-way pop-under.
• You can't press 'escape' to get rid if the pop-up should you change your mind.

Expected behavior:

• Since a form control that you can type in pops up, I expect to be able to type in it without extra clicks.
• Make it close when you press escape.

Additional context

Firefox, both Linux and Windows.