Handle all user generated code errors in the type checker (#394)

* Move the missing_definition error to the type checker

* Move the parameterised_event and parameterised_state errors to the type checker

* Remove check_state_and_event_types from ast_to_fcode

* Move missing_init_function to the type checker

* Remove the code error last_declaration_must_be_main_contract

* Expand the tests for missing init function

* Remove found_void error

* Move the higher order entrypoint error to type checker

* Move invalid_aens_resolve_type error to type checker

* Add more tests for AENS.resolve

* Add test for AENS.resolve with using

* Move invalid_oracle_type error to type checker

* Move old code errors tests to compilable_contracts

* Remove the file aeso_code_errors.erl

* Add comment about state type

test/contracts/name_clash.aes

@@ -1,12 +1,5 @@
-
 contract NameClash =
 
-  entrypoint double_proto : () => int
-  entrypoint double_proto : () => int
-
-  entrypoint proto_and_def : int => int
-  entrypoint proto_and_def(n) = n + 1
-
   entrypoint double_def(x) = x
   entrypoint double_def(y) = 0
 
@@ -14,4 +7,4 @@ contract NameClash =
   entrypoint abort() : int = 0
   entrypoint require(b, err) = if(b) abort(err)
   entrypoint put(x) = x
-  entrypoint state(x, y) = x + y
+  entrypoint state(x, y) = x + y