Added a vector to check for banned vals during report validation

Author: davxy

stf/reports/full/banned_validator_guarantee-1.bin

@@ -115,7 +115,8 @@ ErrorCode ::= ENUMERATED {
     too-many-dependencies (19),
     segment-root-lookup-invalid (20),
     bad-signature (21),
-    work-report-too-big (22)
+    work-report-too-big (22),
+    banned-validator (23)
 }
 
 Output ::= CHOICE {

stf/reports/full/banned_validator_guarantee-1.json

@@ -99,4 +99,5 @@ class ReportsTestVector(StfTestVector):
         20: "segment_root_lookup_invalid",
         21: "bad_signature",
         22: "work_report_too_big",
+        23: "banned_validator"
      }