Add contest bot webhook

[rbennettcw]

Link to Issue

Closes: #10375
Closes: #10628

Description of Changes

• Implements contest bot to launch contests via farcaster post

Test Plan

• Using the private key account, create a new community w/ namespace
• In neynar dashboard, create new webhook called ContestBotMentioned (YourName)
  • Set target to <your ngrok domain>/api/integration/farcaster/CastUpvoteAction
  • Filter on Cast Created + mentioned FIDs and enter 948630

Set envs:

• NEYNAR_BOT_UUID (from Neynar, CW Local app)

• NEYNAR_CONTEST_BOT_MENTIONED_WEBHOOK_SECRET (from Neynar, CW Local app)

• CONTEST_BOT_NAMESPACE (namespace must be created by bot wallet)

• CONTEST_BOT_PRIVATE_KEY (same as the PRIVATE_KEY)

• On warpcast, post cast to commondemo bot: hey @commondemo create a contest with the token 0x429ae85883f82203D736e8fc203A455990745ca1 with 25% of prize amount allocated to voters and a third to each of three winners. The contest title is “new contest 123”. Use the following image https://placehold.co/600x400/EEE/31343C

• Wait a few second for a reply– confirm that it's a contest frame posted by the bot

Deployment Plan

Set envs:

• NEYNAR_BOT_UUID
• NEYNAR_CONTEST_BOT_MENTIONED_WEBHOOK_SECRET
• CONTEST_BOT_NAMESPACE
• CONTEST_BOT_PRIVATE_KEY

Other Considerations

N/A

[Rotorsoft]

Commands should be using imperative names describing the action, for consistency. In this case we are relaying Neynar events to the Outbox... so, we should probably start a convention here like RelayFarcasterContestBotMentioned or something similar that's easy to find when looking for all relays