Handle long names gracefully

[FarisZR]

Currently, if a user has a very long name on matrix (or another bridged platform) the discord bridge will reply with this error ⚠ Your message was not bridged: 50035: Invalid Form Body

It would be great if the bridge could just automatically trim names to the maximum length allowed by discord, maybe notify the user on their first message in the chat room about this.

[TheAwiteb]

maybe notify the user on their first message in the chat room about this.

I think this will just make it more complicated, Discord allows a maximum of 32 and a minimum of 2 for display name length. So I think a display name longer than 32 doesn't make sense, so using the first 32 characters is enough.