Extend cast character limit

[hellno]

Is your feature request related to a problem? Please describe.
herocast is still using an old character limit. For a while, Farcaster and Warpcast supports longer casts.
We don't allow this yet and we want to unblock this.

Additional context
When rendering a cast, usually there is a fold meaning some part of the text is above a fold and a button is shown to unfold / unwrap the text to show everything. this isn't part of this issue