feat(nfs3_client): add is_connection_reusable method to error types

[Vaiz]

Adds an is_connection_reusable method to all error types in nfs3_client, letting callers decide whether a connection can be kept after an error without inspecting individual variants

[Copilot]

Pull request overview

Adds a lightweight API to nfs3_client error types so callers can decide whether an underlying connection can be safely reused after an error, without needing to match on individual error variants.

Changes:

• Documented connection state semantics for RpcClient::call and RpcError.
• Added is_connection_reusable() inherent methods to RpcError, PortmapError, MountError, and ConnectError.
• Updated the clippy::similar_names suppression on RpcClient::call to use #[expect(..., reason = ...)].

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
crates/nfs3_client/src/rpc.rs	Documents how callers should decide whether to reuse a connection after call() errors; updates clippy suppression style.
crates/nfs3_client/src/error/rpc.rs	Adds RpcError::is_connection_reusable() and documents connection-state considerations.
crates/nfs3_client/src/error/portmap.rs	Adds PortmapError::is_connection_reusable() delegating to RpcError when applicable.
crates/nfs3_client/src/error/mount.rs	Adds MountError::is_connection_reusable() delegating to RpcError when applicable.
crates/nfs3_client/src/error/connect.rs	Adds ConnectError::is_connection_reusable() delegating to nested errors.