Python: Add RESET command support

[affonsov]

Summary

Adds support for the RESET command to the Python client (async and sync). RESET resets the connection state.

Issue link

This Pull Request is linked to issue: Implement RESET command for Python, Node.js, Go, and Java clients
Closes #5942

Features / Behaviour Changes

• reset() added to CoreCommands (async and sync), available on both standalone and cluster clients
• reset() added to BaseBatch for pipeline/batch support

Implementation

• Sends RequestType.Reset with no arguments; returns "RESET" on success

Limitations

None.

Testing

• Integration tests verify the command returns "RESET"
• Core-level state tracking (reconnect behavior, pub/sub cleanup, cluster routing) is tested in the glide-core PR: Core: track post-RESET connection state in handle_reset_command #5959

Checklist

• This Pull Request is related to one issue.
• Commit message has a detailed description of what changed and why.
• Tests are added or updated.
• CHANGELOG.md and documentation files are updated.
• Linters have been run (make *-lint targets) and Prettier has been run (make prettier-fix).
• Destination branch is correct - main or release
• Create merge commit if merging release branch into main, squash otherwise.

[alexr-bq]

Changelog entry?