Unify default location for config files for different startup methods

[NoahMaizels]

Summary

Currently, running Bee using bee start vs sudo systemctl start bee uses two different default locations for the configuration file. This is confusing and non-intuitive, so unless there is a good technical reason to have two different default locations for different startup methods, I believe that the default startup location should be unified to a single default location.

Motivation

To simplify UX., especially for newcomers to Swarm who are going through the initial onboarding process

Implementation

No

Drawbacks

It will be a change which existing Bee users will need to get used to.