Show session name in the Delete Session confirmation dialog

Summary:
Updated the Delete Session confimation to include chosen session name. Revision D13444 has been abandoned so I finished it.
Related: BUG 393138

Reviewers: KDevelop, apol

Reviewed By: KDevelop, apol

Subscribers: apol, kdevelop-devel

Tags: KDevelop

Differential Revision: https://phabricator.kde.org/D22456