add test cases for several FORMERR code paths:

- duplicated question
  - duplicated answer
  - qtype as an answer
  - two question types
  - question names
  - nsec3 bad owner name
  - short record
  - short question
  - mismatching question class
  - bad record owner name
  - mismatched class in record
  - mismatched KEY class
  - OPT wrong owner name
  - invalid RRSIG "covers" type
  - UPDATE malformed delete type
  - TSIG wrong class
  - TSIG not the last record

(cherry picked from commit 6e9ed4983e)

bin/tests/system/formerr/dupquestion

@@ -0,0 +1,10 @@
+# header: 2 questions
+00 00 00 00 00 02 00 00 00 00 00 00
+# question: AAAAAAAAAAAAAA./A/IN
+0e 41 41 41 41 41 41 41 41 41 41 41 41 41 41 00
+00 01
+00 01
+# question: AAAAAAAAAAAAAA./A/IN
+0e 41 41 41 41 41 41 41 41 41 41 41 41 41 41 00
+00 01
+00 01