feat(pool): Connection pool distinguishes request versions

[0x676e67]

This pull request includes changes to the src/util/client/mod.rs and src/tls/mod.rs files to enhance the functionality and improve the code structure. The most important changes involve adding a new field to the PoolKey struct, modifying the Dst struct and its methods, and updating the AlpnProtos struct to derive the Hash trait.

Enhancements to PoolKey and Dst structs:

• src/util/client/mod.rs: Added alpn_protos field to the PoolKey struct and updated its new method to accept this field.
• src/util/client/mod.rs: Removed the alpn_protos field from the Dst struct and updated the new method to use the alpn_protos field from PoolKey.
• src/util/client/mod.rs: Updated the alpn_protos method in Dst to retrieve the value from PoolKey and added a new is_h2 method to check if the ALPN protocol is HTTP/2.
• src/util/client/mod.rs: Updated the ver variable assignment to use the new is_h2 method in Dst.

Deriving Hash trait for AlpnProtos:

• src/tls/mod.rs: Modified the AlpnProtos struct to derive the Hash trait.