core: enable log level based logging

[scriptnull]

Currently, we have three types of logs:

• verbose
• error
• debug

All of them are getting printed now. We will need to introduce a env which could be used by waymond to determine which log types to print. The env name could be WAYMOND_LOG_LEVEL. Setting it to debug should print all three types. Setting it to verbose should print verbose and error logs. Setting it to error should log only the errors.

Related code is present in https://github.com/scriptnull/waymond/tree/main/internal/log