databases/sqlite3: enable OS features

Enable various FreeBSD API options and go-fasters

The only one of these that raised concern is related to mmap, but this
compile time flag will not enable mmap usage on its own.

There is a test failure on ZFS with posix_fallocate(), leave that off
for now.

PR: 241385
Tested by: kbowling (test harness https://www.sqlite.org/testing.html)
Approved by: maintainer timeout