x11/plank: Moved from x11-wm/plank, updated to 0.11.89

• Various adjustments/fixes and preparations for 0.12.0
• Port moved as incorrectly labeled under windows manager but is an independent dock application.
• Give maintainership to Daniel Shafer <daniel@shafer.cc>

PR: 241302
Submitted by: Daniel Shafer <daniel@shafer.cc> (maintainer)
Differential Revision: https://reviews.freebsd.org/D22029