refactor: structure of an hexagonal architecture

Created a kernel crate to store models and future action implementations.
Will be useful to create admin cli.

tests/hurl_integration/scenario_1/config.toml

@@ -0,0 +1,56 @@
+[instance]
+base_uri = "http://localhost:8086"
+name = "Example org"
+logo_uri = "https://example.org/logo.png"
+
+[[applications]]
+slug = "demo_app"
+name = "Demo app"
+description = "A super application where you can do everything you want."
+client_id = "00000001-0000-0000-0000-000000000001"
+client_secret = "dummy_client_secret"
+login_uri = "https://localhost:9876"
+allowed_redirect_uris = [
+    "http://localhost:9090/callback",
+    "http://localhost:9876/callback"
+]
+visibility = "Internal"
+authorize_flow = "Implicit"
+
+[[applications]]
+slug = "wiki"
+name = "Wiki app"
+description = "The knowledge base of the exemple org."
+client_id = "f9de1885-448d-44bb-8c48-7e985486a8c6"
+client_secret = "49c6c16a-0a8a-4981-a60d-5cb96582cc1a"
+login_uri = "https://wiki.example.org/login"
+allowed_redirect_uris = [
+    "https://wiki.example.org/oauth2/callback"
+]
+visibility = "Public"
+authorize_flow = "Implicit"
+
+[[applications]]
+slug = "private_app"
+name = "Demo app"
+description = "Private app you should never discover"
+client_id = "c8a08783-2342-4ce3-a3cb-9dc89b6bdf"
+client_secret = "this_is_the_secret"
+login_uri = "https://private-app.org"
+allowed_redirect_uris = [
+    "http://localhost:9091/authorize",
+]
+visibility = "Private"
+authorize_flow = "Implicit"
+
+[[roles]]
+slug = "basic"
+name = "Basic"
+description = "Basic user"
+default = true
+
+[[roles]]
+slug = "admin"
+name = "Administrator"
+description = "Full power on organization instance"
+