Refactor to use flags and env-vars instead of config file

[samlaf]

My main reason for this is outlined in https://www.arp242.net/flags-config.html

### Tasks
- [ ] https://github.com/Layr-Labs/incredible-squaring-avs/issues/57
- [ ] Refactor node

[samlaf]

Also flags will lead to less bugs due to outdated addresses in config files. See for eg #42 (comment)

[samlaf]

@0xpanicError you interested in doing this?

[0xpanicError]

Yes would love to take this