Persist path for "Copy/Move/Link To" to config file

Summary:
Additional patch to make the targetUrl persistent again.
Modified storage of dirpath only instead of filepath.
Save temporarily stored path of Copy/Move/Link To file dialogues from ContextManager in rc-file and restore on next start.

CCBUG: 362474

Reviewers: rkflx

Reviewed By: rkflx

Subscribers: ngraham, dhaumann, rkflx

Differential Revision: https://phabricator.kde.org/D8785