Consider moving the rest of chain types to ergo-chain-types

### Motivation
- To keep them in one place vs splitting between `ergotree-ir` and `ergo-lib`.
- Chain types come with JSON encoding and serialization attached which does not fit well in `ergotree-ir`.
- Chain types heavily depend on each other.

### Implementation details
The main pain point will be `ErgoBox::ergo_tree`. Since `ErgoTree` belongs to `ergotree-ir` and `ErgoBox` is used in `ergotree-ir`, one way would be to make `ErgoBox::ergo_tree` a serialized `ErgoTree`. However, `ErgoBox` deserialization depends on `ErgoTree` deserialization which is in `ergotree-ir`.

EIP-12 related types for special number-as-strings JSON encoding from ergo-lib-wasm were also copied to ergo-lib-c-core.