Add a getBotId utility function

[haseebrabbani]

Currently a bot does not have a way to get its own bot ID (unless its hardcoded). The SDK should provide a getBotId helper method to achieve this.

The bot ID is either read from a local forta.config.json (set by the agentId property), OR calculated by hashing the package.json name property. The presence of the forta.config.json field can change the returned botId value. We need to determine how to provide the same value all the time.

Ideally we should not copy forta.config.json into the container since it can have sensitive information (e.g. RPC API keys). then it follows that maybe we should move the botId into package.json (and stop hashing the package.json name altogether)