qapi: rename 'special_features' to 'features'

This updates the QAPI code generation to refer to 'features' instead
of 'special_features', in preparation for generalizing their exposure.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-ID: <20250205123550.2754387-4-berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Imports tidied up with isort]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

scripts/qapi/commands.py

@@ -25,7 +25,7 @@ from .gen import (
     QAPIGenC,
     QAPISchemaModularCVisitor,
     build_params,
-    gen_special_features,
+    gen_features,
     ifcontext,
 )
 from .schema import (
@@ -298,7 +298,7 @@ def gen_register_command(name: str,
 ''',
                 name=name, c_name=c_name(name),
                 opts=' | '.join(options) or 0,
-                feats=gen_special_features(features))
+                feats=gen_features(features))
     return ret