Use a more intuitive, user-friendly name for Samba share access

Summary:
"Samba shares" is a jargonistic term that won't mean much to most people. This patch replaces it with a more intuitive and user-friendly term.

BUG: 141257
FIXED-IN: 18.08.0

Test Plan:

Reviewers: Frameworks, Dolphin, VDG, apol, markg

Reviewed By: apol, markg

Subscribers: markg, ltoscano, elvisangelaccio

Differential Revision: https://phabricator.kde.org/D12765