Removing the channel title in the messages table

[andreg]

What problem does this address?

By looking at the notifications_messages table, I think that perhaps the channel_title field is no longer needed, since the relationship of a notification Message with the Channel is established through the channel_name field already, and the human-readable title for the Channel can be fetched by accessing the Channels Registry with Channel_Registry::get_registered, instead.

What is your proposed solution?

To remove the channel_title column from the notifications_messages table.

Please confirm that you have searched existing issues in the repo.

Yes