jp (base, pubsub/set): new --quiet argument:

`--quiet` can be used to only return essential data from command. This is notably useful
to remove message and trailing line feed when returning a data which must be parsed by an
other program.

sat_frontends/jp/base.py

@@ -316,6 +316,11 @@ class Jp(object):
             '--verbose', '-v', action='count', default=0,
             help=_("Add a verbosity level (can be used multiple times)"))
 
+        quiet_parent = self.parents['quiet'] = argparse.ArgumentParser(add_help=False)
+        quiet_parent.add_argument(
+            '--quiet', '-q', action='store_true',
+            help=_("be quiet (only output machine readable data)"))
+
         draft_parent = self.parents['draft'] = argparse.ArgumentParser(add_help=False)
         draft_group = draft_parent.add_argument_group(_('draft handling'))
         draft_group.add_argument(

sat_frontends/jp/cmd_pubsub.py

@@ -734,6 +734,7 @@ class Set(base.CommandBase):
             host,
             "set",
             use_pubsub=True,
+            use_quiet=True,
             pubsub_flags={C.NODE},
             help=_("publish a new item or update an existing one"),
         )
@@ -770,7 +771,10 @@ class Set(base.CommandBase):
             self.host.quit(C.EXIT_BRIDGE_ERRBACK)
         else:
             if published_id:
-                self.disp("Item published at {pub_id}".format(pub_id=published_id))
+                if self.args.quiet:
+                    self.disp(published_id, end='')
+                else:
+                    self.disp(f"Item published at {published_id}")
             else:
                 self.disp("Item published")
             self.host.quit(C.EXIT_OK)