columnviewtitle: Prevent header clicks from propagating

The header in GtkColumnView has multiple event handlers there is a ::pressed handler in GtkColumnView for resizing the columns in CAPTURE as well as a motion and drag controller. The ::release handler is in GtkColumnViewTitle. We can't claim the event in the existing handlers because then the ::release handler will never get called. Currently, however, all clicks get propagated to the ColumnView from the header which can be problematic. Since we don't usually want the clicks from the header handled on the view, claim it in the BUBBLE phase.

Fixes: #5425 (closed)