x11/polybar: update to version 3.3.0.

• disable network support early since it needs Linux/libnl
• add CURSOR, PULSEAUDIO, and XKEYBORAD options
• remove unused EXAMPLES option
• rename CURL option to GITHUB
• rewrite some OPTIONS descriptions

Reviewed by: tcberner (mentor)
Approved by: mat (mentor)
Differential Revision: https://reviews.freebsd.org/