C#: Introduce extractor option for logging verbosity

csharp/codeql-extractor.yml

@@ -48,3 +48,21 @@ options:
       The default is 'true'.
     type: string
     pattern: "^(false|true)$"
+  logging:
+    title: Options pertaining to logging.
+    type: object
+    properties:
+      verbosity:
+        title: Extractor logging verbosity level.
+        description: >
+          Controls the level of verbosity of the extractor.
+          The supported levels are (in order of increasing verbosity):
+            - off
+            - errors
+            - warnings
+            - info or progress
+            - debug or progress+
+            - trace or progress++
+            - progress+++
+        type: string
+        pattern: "^(off|errors|warnings|(info|progress)|(debug|progress\\+)|(trace|progress\\+\\+)|progress\\+\\+\\+)$"