Phone: standardize appearance and translation of extension label

[agh1]

Overview

Phone extensions should appear consistently, with "ext." wrapped in ts for translation and the opportunity for a break before the label.

Before

Event phone numbers have "x" between the phone number and extension fields, while other forms have "ext." All inline spaces are non-breaking spaces, forcing the phone number, extension label, and extension into a single line no matter how narrow the context.

After

Inline contact edit, the contact edit form, and the event location form all have phone numbers and extensions composed the same way. The phone field is followed by a regular space, then "ext." (translatable), a non-breaking space, and the extension field.

The ts function is given the context phone_ext to clarify that it's a phone extension rather than one of the many other possibilities for the letters "ext."

Comments

See the related Mattermost discusson.

[eileenmcnaughton]

merging as this affects wording & translation & was canvassed during chat. (Clearly my preference for capitalizing 'Ext.' was not heeded :-)