FIX: ensure Gridliner is up-to-date for title adjustment

[rcomer]

Rationale

Fixes #2390. Add an extra call to _draw_gridliner within the title adjustment code but only if top or geo labels are switched on.

Implications

This caused a small shift in position in the existing image test which uses constrained layout. The RMS was only 3.9 but since this is a genuine behaviour change I think it makes sense to replace the baseline image rather than increase the tolerance.

[rcomer]

Note that _draw_gridliner doesn't actually do any drawing. It just creates or updates the lines and labels. I would like to rename it to something like _update_children but don't mind whether that happens here or in a separate PR.