fix: baninfo interaction response

[Akinator31]

This pull request refactors how ban information responses are sent, unifying the logic for both text and slash commands by introducing a new BaninfoReplyTarget enum. This makes the response handling more flexible and maintainable, allowing responses to be sent either to a channel or as a follow-up to an interaction. Additionally, the signature and return type of send_baninfo_response have been updated to support this change and improve error handling.

Unified response handling for baninfo commands:

• Introduced the BaninfoReplyTarget enum in baninfo.rs to abstract over reply targets, supporting both channel messages and interaction follow-ups. ([crates/rustmail/src/commands/baninfo/text_command/baninfo.rsR119-R139](https://github.com/Rustmail/rustmail/pull/493/files#diff-5d8c70530a6da235ce2b84e60fb01fefebc0e56625e146bfbdc0cbc23e095743R119-R139))
• Updated send_baninfo_response to accept a BaninfoReplyTarget instead of a channel ID, and to return a ModmailResult<()> for better error propagation. ([[1]](https://github.com/Rustmail/rustmail/pull/493/files#diff-5d8c70530a6da235ce2b84e60fb01fefebc0e56625e146bfbdc0cbc23e095743R119-R139), [[2]](https://github.com/Rustmail/rustmail/pull/493/files#diff-5d8c70530a6da235ce2b84e60fb01fefebc0e56625e146bfbdc0cbc23e095743L143-R165))
• Refactored both text and slash command handlers to use the new BaninfoReplyTarget when calling send_baninfo_response. ([[1]](https://github.com/Rustmail/rustmail/pull/493/files#diff-3614c746b4cdd6b30d4f30dd3b4c213d26c4da0922203f8ba3c7f729014ad19bL1-R3), [[2]](https://github.com/Rustmail/rustmail/pull/493/files#diff-3614c746b4cdd6b30d4f30dd3b4c213d26c4da0922203f8ba3c7f729014ad19bL99-R108), [[3]](https://github.com/Rustmail/rustmail/pull/493/files#diff-5d8c70530a6da235ce2b84e60fb01fefebc0e56625e146bfbdc0cbc23e095743L41-R50))

Improvements to message building:

• Enhanced the MessageBuilder logic to prioritize a custom embed if present when building interaction follow-ups, improving flexibility in message formatting. ([crates/rustmail/src/utils/message/message_builder.rsL565-R567](https://github.com/Rustmail/rustmail/pull/493/files#diff-a13904fa9ae13cee8b5d65f68e64409a79431f10d8da3fb6f4aaf2dde1ab26b1L565-R567))