Oneliner submission field for oneliner source strings to save space

[comradekingu]

instead of

Edit: With two lines, there is less vertical space to show other strings if doing singleline translations, because the second line of the editor goes to waste

The idea is to have the translator field be one field by default, and expand when another line is added The second part of that works already, so it just needs to start out at one line.

[dwaynebailey]

@comradekingu if you can PR this as a change we can show you how to stage this for testing.

[comradekingu]

Pootle 2.9.0rc1 Translate Toolkit 2.2.5.