fix: remove hard-deleted thread replies shown in the channel from the message list

[RaphaelFakhri]

Title: fix: remove hard-deleted thread replies shown in the channel from the message list

CLA

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• Code changes are tested

Description of the changes, What, Why and How?

ChannelState.removeMessage removes a thread reply from threads[parent_id] and skips the channel message sets (if / else). A reply sent with show_in_channel: true exists in both places, so a message.deleted event with hard_delete removed it from the thread only and left it in channel.state.messages.

removeMessage now also removes the message from the channel message sets when show_in_channel is true, or when the thread is not loaded (the previous behavior). The show_in_channel field is read from the message passed by the message.deleted handler.

A test in channel_state.test.js hard-deletes a reply that is shown in the channel and checks both lists. The test fails on the previous code and passes with this change. channel_state.test.js and channel.test.js pass (235 tests).

Changelog

• Fix hard-deleted thread replies with show_in_channel staying in the channel message list.