#5268 Check for node API key when starting a strategy that uses gateway

gateway

• default RPC for avalanche is now Moralis
• update docker setup script to handle null value correctly

hummingbot

• in gateway create, make Infura API key optional
• after calling start, check if gateway is required, then check the chain/network for API keys. If the API key does not exist, prompt the user to input it

Link: https://github.com/hummingbot/hummingbot/pull/5268