Support Hints

[lucidLuckylee]

We should support hints directly in the StructuredScript struct so that the chunker can provide the correct hints as input for each chunk.
This is actually very similar to BitVM/BitVM#13 but instead of an OP_PUSH opcode we support OP_HINT.

[lucidLuckylee]

I am thinking it could look like this:

OP_HINT "identifier" and at runtime a dictionary for the identifiers and their values is provided. Ideally we also support non-static strings with something like OP_HINT { some_string}