Exclude KMS account client from the Debug impl

[squadgazzz]

KMS account client's debug information is too verbose, which is not useful. The proposal is to exclude this from the Debug impl entirely.

[Copilot]

Pull Request Overview

This PR customizes the Debug implementation for the KMS Account struct to exclude the verbose client field output while retaining debug information for key_id and address fields.

• Replaces the derived Debug trait with a custom implementation
• Excludes the client field from debug output to reduce verbosity
• Maintains debug information for key_id and address fields

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[jmg-duarte]

LGTM, sad that Rust doesn't have something like #[debug(skip)] because for longer structs this would be kind of annoying to implement

[MartinquaXD]

LGTM, sad that Rust doesn't have something like rust-lang/rust#37009 (comment) because for longer structs this would be kind of annoying to implement

@jmg-duarte, it's not built in but this can be done with the derivative crate (see here).