Add a function to invoke an entrypoint of a contract
semantics.eval
can be called to execute a smart contract script but only if we have a toplevel parameter. However, a read contract call actually contains an (entrypoint, argument) pair.
We already have a function in syntax.v to search for an entrypoint in the parameter type so defining a function to invoke a contract entrypoint is probably just a matter of pluging it on top of semantics.eval.
This issue is a very preliminary step toward modeling smart-contract interactions. See https://gitlab.com/nomadic-labs/coquille/-/issues/5.