Refactor/project structure (#3085)

* refactor project structure

* environment-based default registry

* fix tests

* update build container

* use docker platform for iso build emulation

* simplify compat

* Fix docker platform spec in run-compat.sh

* handle riscv compat

* fix bug with dep error exists attr

* undo removal of sorting

* use qemu for iso stage

---------

Co-authored-by: Mariusz Kogen <k0gen@pm.me>
Co-authored-by: Matt Hill <mattnine@protonmail.com>

web/config-sample.json

@@ -11,5 +11,6 @@
       "skipStartupAlerts": true
     }
   },
+  "defaultRegistry": "https://registry.start9.com",
   "gitHash": ""
 }