bitbake: bitbake-layers: use parsable title for show-appends

Print title text surrounded by === as we do with other subcommands so
that you can filter it out in scripts. (You will also want to filter out
lines starting with "WARNING:" if you just want the list).

(Bitbake rev: ba15ba16a5d863886bcfd5b3f0bdfff2a6de11a0)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/bin/bitbake-layers

@@ -521,7 +521,7 @@ Recipes are listed with the bbappends that apply to them as subitems.
             logger.plain('No append files found')
             return
 
-        logger.plain('State of append files:')
+        logger.plain('=== Appended recipes ===')
 
         pnlist = list(self.cooker_data.pkg_pn.keys())
         pnlist.sort()