fix(move): move command doesnt sync permissions

[Akinator31]

This pull request introduces several improvements to how channels are moved between categories in the rustmail project, focusing on permission management and error handling. The main changes include updating the version, refactoring functions to use custom error types, and ensuring that permission overwrites are preserved when moving channels.

Permission management improvements:

• Added the get_category_permissions_overwrites function in category.rs to retrieve permission overwrites from a category before moving a channel, ensuring permissions are correctly transferred.
• Updated move_channel_to_category_by_msg and move_channel_to_category_by_command_option in common.rs to apply category permission overwrites when moving channels, improving consistency and security.

Error handling and type safety:

• Refactored functions to use the custom ModmailResult and ModmailError types instead of raw Serenity errors, standardizing error handling across the codebase. [1] [2] [3]

General updates:

• Updated the project version in Cargo.toml from 0.1.1 to 1.0.3 to reflect these significant changes.