* `strings`: More roubust type checking of keys/IDs, coerce `int`-like types to `hash_t`
* Preserve existing public API behaviour
* Fix return type
* Replace `bool` with `bint`, rename to `_try_coerce_to_hash`, replace `id` with `hash`
* Avoid unnecessary re-encoding and re-calculation of strings and hashs respectively
* Rename variables named `hash`
Add comment on early return