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/047/validators/foo.ak

@@ -1,5 +1,5 @@
-validator spend {
-  fn(_datum: Void, _redeemer: Void, _ctx: Void) -> Bool {
+validator {
+  fn spend(_datum: Void, _redeemer: Void, _ctx: Void) -> Bool {
     True
   }
 }