Cardano Updates

  Turns out that 'serialise_data' does actually re-encode values, which
  is unlike the ledger when building the script context an computing
  datum hashes.

  While this can be confusing, this is actually the world we live in and
  the actual VM semantic :|

  Fixes #1203.

Signed-off-by: KtorZ <[email protected]>

do not curry non-constant terms into builtins

  This is actually unsound, since non-constant terms may contain
  other arbitrary builtins. With more context, we could actually assert
  whether a term pointed by a Var is "safe to curry" (as in, is pure)
  but that's more involved as a fix.

  The main goal of this optimisation is to actually pre-apply and hoist
  builtins that are repeatedly applied to common constants (e.g.
  comparison to zero); it isn't particularly useful (and quite wrong!)
  to do so for *any* arbitrary term.

  Fixes #1278.

Signed-off-by: KtorZ <[email protected]>