feat(server): role based authentication system (#2434)

- Parse toml configuration file, see https://github.com/qdm12/gluetun-wiki/blob/main/setup/advanced/control-server.md#authentication
- Retro-compatible with existing AND documented routes, until after v3.41 release
- Log a warning if an unprotected-by-default route is accessed unprotected
- Authentication methods: none, apikey, basic
- `genkey` command to generate API keys

Co-authored-by: Joe Jose <45399349+joejose97@users.noreply.github.com>

internal/configuration/settings/settings_test.go

@@ -70,7 +70,8 @@ func Test_Settings_String(t *testing.T) {
 |   └── Enabled: no
 ├── Control server settings:
 |   ├── Listening address: :8000
-|   └── Logging: yes
+|   ├── Logging: yes
+|   └── Authentication file path: /gluetun/auth/config.toml
 ├── Storage settings:
 |   └── Filepath: /gluetun/servers.json
 ├── OS Alpine settings: