Use LIB_DEPENDS when appropriate in KDE components.

Lots of KDE components are providing libraries, and they were,
strangely, written as BUILD_ or RUN_DEPENDS, with a full path to the
library. Change this so that if a component is needed at both build,
and, run-time, then it gets a LIB_DEPENDS.

Reviewed by: rakuco, tcberner
Sponsored by: Absolight
Differential Revision: https://reviews.freebsd.org/D7625