[Ceres]: Add arbitrary size byte arrays (#456)

* Extend compiler to allow bytes()/bytes as type

* Add split_any, to_fixed_size, size, to_any_size, Int.to_bytes and String.to_bytes

* Add tests

* Use and and not andalso in unify, some things have side-effects

* Bump to aebytecode v3.3.0

* Changelog + update documentation

* fix wording in documentation

priv/stdlib/String.aes

@@ -1,5 +1,8 @@
 include "List.aes"
 namespace String =
+  // Gives a bytes() representation of the string
+  function to_bytes(s : string) : bytes() = StringInternal.to_bytes(s)
+
   // Computes the SHA3/Keccak hash of the string
   function sha3(s : string) : hash    = StringInternal.sha3(s)
   // Computes the SHA256 hash of the string.