Support TCRYPT in ShellMountPasswordDialog
Support unlocking TCRYPT volumes via the ShellMountPasswordDialog.
Adds UI elements to the dialog in order to allow the user to supply the parameters required for TCRYPT volumes.
Requires the patches to glib from this merge request (merged and released in glib 2.57.2).
See also the corresponding merge request to GVfs (merged and released in GVfs 1.37.4).