This adjusts the session ID generator making it use it's own random function rather than using one from the utils lib. This allows us to utilize crypto/rand or math/rand interchangeably. Additionally refactor the utils.RandomString func.
This commit replaces github.com/spf13/viper with github.com/knadh/koanf. Koanf is very similar library to viper, with less dependencies and several quality of life differences. This also allows most config options to be defined by ENV. Lastly it also enables the use of split configuration files which can be configured by setting the --config flag multiple times.
Co-authored-by: Amir Zarrinkafsh <nightah@me.com>