Add MongoDB handshake client metadata for connection identification

[Abhinavkr24]

Currently MongoDB connections created through utopia-php/mongo
appear as anonymous PHP driver connections.

This makes it difficult to identify which connections belong to
applications using this package (such as Appwrite) when debugging
slow queries, connection spikes, or server logs.

According to MongoDB handshake specifications, wrapping libraries
should provide client metadata using the client field during the
initial handshake (hello / isMaster).

Proposal:

• Add configurable application name support
• Send driver metadata during handshake
• Allow downstream applications like Appwrite to set appName