[NEW] Add unread options for direct messages

[sampaiodiego]

@RocketChat/core

In addition to #7477 this PR adds an option to configure the count behavior for direct messages:

The default option is increase the counter for all messages and will looks like this:

When set for mentions only:

• new messages will turn it bold only like this:
  

• group mentions (@all and @here) will looks like this:
  

• and direct mentions (@username) will looks like this:
  

[geekgonecrazy]

The default behaviour I like. But I don't understand the need or want to mention someone in a DM? In my opinion mentions in direct messages are completely pointless.. You don't need draw attention in a 2 party room. Your message is always to the other person.

Sending a message in a DM I think should be exactly the same whether someone mentions you or not.

My usage of other chat platforms... i've never seen a mention in a DM treated any differently then a normal message.

Every time someone mentions me in a DM I cringe... To me it makes absolutely no sense. I'd really hate to start encouraging that behaviour

[sampaiodiego]

I have to say that I agree with you @geekgonecrazy .. this PR is per @rodrigok 's request.

I think since we didn't have time to discuss about #7580 and #7589 this PR is a good opportunity for it.

I personally like the old behavior for all counters (they all should look the same IMO)..

since here we are talking about direct messages, I agree the only behavior would be increase a counter for all messages, even if we hardcode this behavior only for DMs.

@RocketChat/core comments are very welcome.