Provide immediate feedback on stdout when running in an interactive
terminal the assumption being we’re dealing with a human.

Both the constructor “Sid.create” and the string format parser must
reject inputs lacking a subauthorities array of at least size one. Since
the array is no longer optional, reorder the the constructor arguments
to match the data representation.

It is still possible to create SIDs without subauthorities via the
“Sid.create_unsafe” constructor. Also, the packet representation will
happily accept them because their definition (as well as that that of
the identical RPC version) does not specify a minimum count.

This is all rather ambiguous and exacerbated by the fact that [MS-DTYP]
happily specifies an invalid SID “S-1-5” as the “NT_AUTHORITY”. However,
both the grammar and the Win API “ConvertStringSidToSidA()” function
reject SA-less inputs as invalid, so we should too.

Get rid of all “StringFmt” APIs involving exceptions.
There is now only the “decode” function which returns
a result type.