Hishel

- Fix `Last-Modified` validation.

- Add `install_cache` function. (95)
- Add sqlite support. (92)
- Move `ttl` argument to `BaseStorage` class. (94)

- Replace `AsyncResponseStream` with `AsyncCacheStream`. (86)
- Add `must-understand` response directive support. (90)

- Add support for Python 3.12. (71)
- Fix connections releasing from the connection pool. (83)

- Add metadata into the response extensions. (56)

- Add support for request `cache-control` directives. (42)
- Drop httpcore dependency. (40)
- Support HTTP methods only if they are defined as cacheable. (37)