MINOR: tools: add several PA_O_* flags in str2sa_range() callers

MINOR: tools: add several PA_O_* flags in str2sa_range() callers

These flags indicate whether the call is made to fill a bind or a server
line, or even just send/recv calls (like logs or dns). Some special cases
are made for outgoing FDs (e.g. pipes for logs) or socket FDs (e.g external
listeners), and there's a distinction between stream or dgram usage that's
expected to significantly help str2sa_range() proceed appropriately with
the input information. For now they are not used yet.