5.1.0-pre.4

Features

• [api] add new automod endpoints in the moderation API (a97a101, #314, #326)
• [api-call] add more info to HttpStatusCodeError (7137551)
• [chat] add sent date tag (c2753f7, #331, #332)

Fixes

• [chat] fix recognition of join failures (884e9df)
• [chat] fix handlers for bad_vip notices that don't contain a username (f61a0f6)
• [eventsub] force plain text header on EventSub verification & root endpoint (1111a1a)
• [eventsub] force more plaintext headers (8afa5b4)