s4/torture: rework stream names tests usage of local xattr call

s4/torture: rework stream names tests usage of local xattr call

Previously this test, that tests for correct conversion of ':' in stream
names, only worked with streams_xattr with "fruit:metadata" set to
"netatalk".

In order to have test coverage for fruit shares with other configs,
split the test into two:

one test creates the stream over SMB and run against all shares, the
other one is the unmodified existing test and is only run against the
share with streams_xattr and fruit:metadata=netatalk.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=13155

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>