[Notifier] Allow to update Slack messages

[maxim-dovydenok]

Update existing SlackTransport to allow message updates. Because chat.update API method only allows channel ids, this PR also includes updates to SentMessage

Q	A
Branch?	6.2
Bug fix?	no
New feature?	yes
Deprecations?	no
Tickets	Fix #47274
License	MIT
Doc PR	symfony/symfony-docs#17214

This pull request allows to update slack messages, for example to keep entity statuses up-to-date:

// On entity creation
$message = sprintf('Entity #%s (%s)', $entity->getId(), $entity->getStatus());
$sentMessage = $this->chatter->send(new ChatMessage($message));

// On status changes
$message = sprintf('Entity #%s (%s)', $entity->getId(), $entity->getStatus());
$this->chatter->send(new ChatMessage($message, new UpdateMessageSlackOptions($sentMessage->getFullMessageId())));

[maxim-dovydenok]

Hello, do I need to do anything else to get a review? Or it's just in the queue?

[nicolas-grekas]

LGTM thanks. I just pushed some changes to make the API a bit more DX-friendly hopefully.

[nicolas-grekas]

Thank you @shiftby.