www/thundercache: Stage support, PGSQL option fix and more

The PR only provided changes needed to add stage support. However, the
port needed some additional TLC:

• DISTNAME reworked for single, ARCH-based definition (pets portlint)
• LICENSE stuff moved, rearranged (pets portlint)
• DOCS option removed (it wasn't implemented)
• Typo for PGSQL option fixed so it's default again (bump portrevision)
• Cosmestic alignment
• PGSQL converted to USES+=pgsql and WANT_PGSQL=
• php+pgsql RUN_DEPENDS refactored, and set to use USE_PHP
• Convert to new LIB_DEPENDS style (PR)
• Convert to USES+=tar (PR)
• Remove WWW whitespace (PR)
• Handle /var/run/thunder (PR) (also requires portrevision bump)

PR: 190951
Submitted by: Joe Benden
fixes by: marino
Approved by: stage blanket + just fix it blanket
verified by: Redports 8x pass