refactor(whatsrust): extract group and chat queries

[Andiveli]

Summary

• Extract group information, participants, chat settings, and DM-resolution wrappers.
• Preserve public APIs, FFI ownership, ABI behavior, error mapping, and endpoint semantics.

Changes

• Moved the remaining query wrappers and focused group-info tests into queries.rs.
• Added explicit facade reexports for every moved public query.

Chain Context

• Immediate parent: PR refactor(whatsrust): extract contacts and communities queries #325.
• Diagram: refactor(whatsrust): extract action wrappers #315 -> refactor(whatsrust): extract read synchronization wrappers #317 -> refactor(whatsrust): extract message payload builders #321 -> refactor(whatsrust): extract outbound message wrappers #324 -> refactor(whatsrust): extract contacts and communities queries #325 -> 📍 this PR -> residual facade cleanup.
• End: all contacts, communities, groups, settings, and DM query wrappers share one owner.

Testing

• cargo fmt --all -- --check
• CARGO_TARGET_DIR=/home/samael/Escritorio/public/wptui-public/target cargo check --workspace --all-targets
• CARGO_TARGET_DIR=/home/samael/Escritorio/public/wptui-public/target cargo test -p whatsrust queries:: -- --test-threads=1
• git diff --check

Review Budget and Rollback

• Authored diff: 247 lines (126 additions + 121 deletions).
• Rollback: revert commit e40bb73.

Closes #326