Rework backing storage system

Step one: Copy the struct definitions over into a new, dedicated
submodule
Step two: Make a generator script
Step three: Define helper functions for various queries

storage-new/models/UserAuthenticationMethod.go

@@ -0,0 +1,26 @@
+package models
+
+import "database/sql/driver"
+
+type AuthenticationMethodType string
+
+const (
+	AuthMethodPassword   AuthenticationMethodType = "password"
+	AuthMethodGAuth      AuthenticationMethodType = "g-auth" // Google Authenticator / totp
+	AuthMethodMail       AuthenticationMethodType = "mail"
+	AuthMethodPasskey2fa AuthenticationMethodType = "passkey-2fa" // Passkey used as 2fa factor
+	AuthMethodPasskey    AuthenticationMethodType = "passkey"     // Passkey as only auth key
+)
+
+var AllAuthMethods = []AuthenticationMethodType{
+	AuthMethodPassword, AuthMethodGAuth, AuthMethodMail, AuthMethodPasskey, AuthMethodPasskey2fa,
+}
+
+func (ct *AuthenticationMethodType) Scan(value any) error {
+	*ct = AuthenticationMethodType(value.([]byte))
+	return nil
+}
+
+func (ct AuthenticationMethodType) Value() (driver.Value, error) {
+	return string(ct), nil
+}