Merge #6585: fix: Do not assert special tx type for cbtx in simplified mn list diff output

fab006d refactor: add var name comment (UdjinM6)
50e4004 fix: Do not assert special tx type for cbtx in simplified mn list difff output (UdjinM6)

Pull request description:

  ## Issue being fixed or feature implemented
  Fixes an edge case for debug builds, release builds aren't affected.

  ## What was done?

  ## How Has This Been Tested?

  ## Breaking Changes
  n/a

  ## Checklist:
  - [ ] I have performed a self-review of my own code
  - [ ] I have commented my code, particularly in hard-to-understand areas
  - [ ] I have added or updated relevant unit/integration/functional/e2e tests
  - [ ] I have made corresponding changes to the documentation
  - [ ] I have assigned this pull request to a milestone _(for repository code-owners and collaborators only)_

ACKs for top commit:
  kwvg:
    utACK fab006d
  knst:
    utACK fab006d
  PastaPastaPasta:
    utACK fab006d

Tree-SHA512: ffe8439e782582eda14d10c80d628272b49fea9e39f8b95186d475b13e1a373573afa68a830639f31138e51f24b763a7fb61df1bc29eb83d3835ba8117e2d228

Author: PastaPastaPasta

src/evo/simplifiedmns.cpp

@@ -279,7 +279,8 @@ UniValue CSimplifiedMNListDiff::ToJson(bool extended) const
     }
     obj.pushKV("newQuorums", newQuorumsArr);
 
-    if (const auto opt_cbTxPayload = GetTxPayload<CCbTx>(*cbTx)) {
+    // Do not assert special tx type here since this can be called prior to DIP0003 activation
+    if (const auto opt_cbTxPayload = GetTxPayload<CCbTx>(*cbTx, /*assert_type=*/false)) {
         obj.pushKV("merkleRootMNList", opt_cbTxPayload->merkleRootMNList.ToString());
         if (opt_cbTxPayload->nVersion >= CCbTx::Version::MERKLE_ROOT_QUORUMS) {
             obj.pushKV("merkleRootQuorums", opt_cbTxPayload->merkleRootQuorums.ToString());