Migrate from chat-api to open-wa for free WhatsApp integration

[smashah]

Is your feature request related to a problem? Please describe. chat-api is quite expensive and all features used in erxes through the existing WhatsApp integration are available readily and free through open-wa (https://github.com/open-wa/wa-automate-nodejs) via self hosting

Describe the solution you'd like Maybe it can be added as a free alternative instead of completely replacing the chat-api integration.

Additional context open-wa has a built in middleware to easily create an API (example), also a super efficient docker implementation is WIP and coming soon.