Review & fix acceptance tests

Temporarily using the 'specialize-dict-key' branch from the stdlib
  which makes use of Pair where relevant. Once this is merged back into
  'main' we should update the acceptance test toml files to keep getting
  them automatically upgraded.

  This commit also fixes an oversight in the reification of data-types
  now properly distinguishing between pairs and 2-tuples.

  Co-authored-by: Microproofs <kasey.white@cardanofoundation.org>

examples/acceptance_tests/script_context/validators/mint.ak

@@ -1,4 +1,5 @@
 use aiken/dict
+use aiken/list
 use aiken/transaction.{Mint, ScriptContext}
 use aiken/transaction/value
 
@@ -36,6 +37,7 @@ fn assert_mint(purpose, transaction) {
 }
 
 fn assert_redeemers(ctx, my_redeemer) {
-  expect Some(redeemer) = dict.get(ctx.transaction.redeemers, ctx.purpose)
-  my_redeemer == redeemer && dict.size(ctx.transaction.redeemers) == 1
+  expect Some(Pair(_, redeemer)) =
+    list.find(ctx.transaction.redeemers, fn(kv) { kv.1st == ctx.purpose })
+  my_redeemer == redeemer && list.length(ctx.transaction.redeemers) == 1
 }

examples/acceptance_tests/script_context/validators/withdrawals.ak

@@ -1,4 +1,4 @@
-use aiken/dict
+use aiken/list
 use aiken/transaction.{ScriptContext}
 use aiken/transaction/credential.{
   Inline, ScriptCredential, VerificationKeyCredential,
@@ -21,15 +21,17 @@ validator {
       )
 
     and {
-      when dict.get(ctx.transaction.withdrawals, alice) is {
+      when
+        list.find(ctx.transaction.withdrawals, fn(kv) { kv.1st == alice })
+      is {
         None -> fail @"alice's withdrawal not found"
-        Some(value) -> value == 42
+        Some(value) -> value.2nd == 42
       },
-      when dict.get(ctx.transaction.withdrawals, bob) is {
+      when list.find(ctx.transaction.withdrawals, fn(kv) { kv.1st == bob }) is {
         None -> fail @"bob's withdrawal not found"
-        Some(value) -> value == 14
+        Some(value) -> value.2nd == 14
       },
-      dict.keys(ctx.transaction.withdrawals) == [alice, bob],
+      list.map(ctx.transaction.withdrawals, fn(kv) { kv.1st }) == [alice, bob],
     }
   }
 }