info-overview: show BUILD_ID in separate row

Previously, if os-release included the BUILD_ID field, it was smushed into the OS Name row as follows:

OS Name                    Endless OS 5.0.0; Build ID: 220810-230009

This is unsightly in English; and in languages where the translations of "OS Name" and "Build ID" are long, the build ID may be ellipsised and hence useless:

Nom du système   Endless OS 5.0.0 ; (identifiant de construction ...
d'exploitation

Instead, display the build ID in a separate row, and hide it if not present.

GNOME OS doesn't have BUILD_ID so for the following screenshot I edited os-release to add it:

And without BUILD_ID:

Fixes: #1347 (closed)