[utils] Add tests for opaque types

We've added opaque types in MetaMask/snaps-monorepo#961. Those types are not testable using normal jest, but we can use tsd to write tests for types like we do in https://github.com/MetaMask/utils/blob/main/src/json.test-d.ts.

We should ensure that `SemVerVersion` and `SemVerRange` are not assignable to each other.

Start with src/json.test-d.ts, which demonstrates the repository's tsd type-test pattern. Add equivalent coverage for SemVerVersion and SemVerRange, checking that neither is assignable to the other; done means the tsd checks pass and reject those assignments.

Written by the indexing model from the issue text.