Add setting to disable indirect messages marker

[tboby]

This is in reference to https://github.com/meetfranz/franz/issues/1190

I think this is an issue because isIndirectMessageBadgeEnabled cannot be set for discord.

Should hasIndirectMessages be set to true in the package.json here?

[Gaboris]

I donj't know about any settings or whatnot, but if someone needs a quick fix till we get a proper option I made a small "hack" in the original thread.
https://github.com/meetfranz/franz/issues/1190#issuecomment-448349236