Cachetoolsutils

Add optional integrity check to `EncryptedCache`.
Code cleanup.
Reorder memcached serialization formats.

Add `full_hash_key` function.
Add `EncryptedCache`, `ToBytesCache` and `BytesCache`.

Add `opts` to provide additional parameters to cached when wrapping methods
and functions.

- Simpler and more compact json cache key function.

- Improve documentation.
- Add experimental `json_key` and `hash_json_key` cache key functions.

- Add `stats` method to return a convenient `dict` of statistics.
- Improve type declarations.
- Add some tests.
- Test with (future) Python 3.14.
- Fix doc typo.