* use exceptions when fetching identity key instead of std::optional, will throw on fail
* fix up config options for endpoint auth and add better docs
* add llarp::serive::AuthType enum for controlling what kind of endpoint auth to use
* rework net code for ip ranges to be cleaner
* clean up endpoint auth code
* refactor config to validate network configs before setting up endpoints
* remove buildone from path/pathbuilder.cpp so we don't spam connection attempts
