Merge #14696: qa: Add explicit references to related CVE's in p2p_invalid_block test.

0c62e3aa73 New regression testing for CVE-2018-17144, CVE-2012-2459, and CVE-2010-5137. (lucash-dev)
38bfca6bb2 Added comments referencing multiple CVEs in tests and production code. (lucash-dev)

Pull request description:

  This functional test includes two scenarios that test for regressions of vulnerabilities, but they are only briefly described. There are freely available documents explaining in detail the issues, but without explicit mentions, the developer trying to maintain the code needs an additional step of digging in commit history and PR conversations to figure it out.
  Added comments to explicitly mention  CVE-2018-17144 and CVE-2012-2459, for more complete documentation.
  This improves developer experience by making understanding the tests easier.

ACKs for top commit:
  laanwj:
    ACK 0c62e3aa73, checked the CVE numbers, thanks for adding documentation

Tree-SHA512: 3ee05351745193b8b959e4a25d50f25a693b2d24b0732ed53cf7d5882df40b5dd0f1877bd5c69cffb921d4a7acf9deb3cc1160b96dc730d9b5984151ad06b7c9

test/functional/feature_block.py

@@ -806,7 +806,7 @@ class FullBlockTest(BitcoinTestFramework):
         #
         # Blocks are not allowed to contain a transaction whose id matches that of an earlier,
         # not-fully-spent transaction in the same chain. To test, make identical coinbases;
-        # the second one should be rejected.
+        # the second one should be rejected. See also CVE-2012-1909.
         #
         self.log.info("Reject a block with a transaction with a duplicate hash of a previous transaction (BIP30)")
         self.move_tip(60)