Make global view properties the default setting

Summary:
Automatic creation of .directory files is one of the most
complained about things in dolphin.

These days applications are supposed to store application-specific data
within $XDG_DATA_HOME. Long-term that's the proper solution for this
issue, but for now we can at least flip the default so that we no longer
create .directory files out of the box.

A tooltip is also added as a kind of warning for the users who want to
change the setting. Ideally a proper warning should be shown using a
KMessageWidget or KMessageBox, but neither play too well with the
setting dialog workflow used by dolphin.

CCBUG: 322922

Reviewers: #dolphin, #vdg, ngraham

Reviewed By: #dolphin, #vdg, ngraham

Subscribers: ngraham, kfm-devel

Tags: #dolphin

Differential Revision: https://phabricator.kde.org/D19661