placeView: Always set text direction to LTR for phone numbers

Since phone numbers are typically displayed using international format (starting with a +) this seems to result in Pango laying out the text with an overall RTL direction in RTL languages, resulting in groups of digits (separated by spaces) being arranged RTL, while the digit groups internally correctly is rendered LTR. And since also eastern Arabic numerals are written left-to-right, just insert a LRM marker to ensure the direction within the text is LTR (setting the text direction of the entire label widget gives off alignment).

Implements #341 (closed)