feat(codegen): support multi-validators

* rename force_wrap to force
* add a bunch of builder methods to Term<Name>
* refactor one tiny location to show off builder methods
* split generate into `generate` and `generate_test`
* create wrap_as_multi_validator function

Co-authored-by: Kasey White <kwhitemsg@gmail.com>

examples/acceptance_tests/077/validators/spend.ak

@@ -2,8 +2,8 @@ use aiken/list.{find, foldr}
 use aiken/transaction.{Input, ScriptContext, Spend}
 use aiken/transaction/value.{add, zero}
 
-validator staking {
-  fn(_datum: Void, _redeemer: Void, context: ScriptContext) -> Bool {
+validator {
+  fn staking(_datum: Void, _redeemer: Void, context: ScriptContext) -> Bool {
     expect Spend(ref) =
       context.purpose
 

examples/acceptance_tests/077/validators/spend2.ak

@@ -1,8 +1,8 @@
 use aiken/list
 use aiken/transaction.{Output, ScriptContext}
 
-validator backtrace {
-  fn(_datum: Void, _redeemer: Void, context: ScriptContext) -> Bool {
+validator {
+  fn backtrace(_datum: Void, _redeemer: Void, context: ScriptContext) -> Bool {
     expect Some(_) =
       list.find(context.transaction.outputs, fn(_) { True })
     let _ =