All #ifndef guards on headers have been removed, I think,
in favor of #pragma once
Headers are now included as `#include "filename"` if the included file
resides in the same directory as the file including it, or any
subdirectory therein. Otherwise they are included as
`#include <project/top/dir/relative/path/filename>`
The above does not include system/os headers.
* 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
