Add the ability to set or redefine attributes for messages in Rabbit.

[pmikle]

One of content_type, content_encoding, message_id, user_id, app_id, delivery_mode, priority, timestamp, expiration, type or reply_to, headers.

[parallels999]

Is this duplicate of #1724?

[pmikle]

Hello, @parallels999 !
1725 for version php 8+, but 1724 for version php 7+.
2 branches for 2 versions of monolog (2.* and 3.*).
Originally, I need this ability for php 7.2 )

[Seldaek]

Merged #1724 into main branch already so closing this