Unify user update methods (#28733)

Fixes #28660
Fixes an admin api bug related to `user.LoginSource`
Fixed `/user/emails` response not identical to GitHub api

This PR unifies the user update methods. The goal is to keep the logic
only at one place (having audit logs in mind). For example, do the
password checks only in one method not everywhere a password is updated.

After that PR is merged, the user creation should be next.

modules/auth/password/pwn.go

@@ -5,24 +5,48 @@ package password
 
 import (
 	"context"
+	"errors"
+	"fmt"
 
 	"code.gitea.io/gitea/modules/auth/password/pwn"
 	"code.gitea.io/gitea/modules/setting"
 )
 
+var ErrIsPwned = errors.New("password has been pwned")
+
+type ErrIsPwnedRequest struct {
+	err error
+}
+
+func IsErrIsPwnedRequest(err error) bool {
+	_, ok := err.(ErrIsPwnedRequest)
+	return ok
+}
+
+func (err ErrIsPwnedRequest) Error() string {
+	return fmt.Sprintf("using Have-I-Been-Pwned service failed: %v", err.err)
+}
+
+func (err ErrIsPwnedRequest) Unwrap() error {
+	return err.err
+}
+
 // IsPwned checks whether a password has been pwned
-// NOTE: This func returns true if it encounters an error under the assumption that you ALWAYS want to check against
-// HIBP, so not getting a response should block a password until it can be verified.
-func IsPwned(ctx context.Context, password string) (bool, error) {
+// If a password has not been pwned, no error is returned.
+func IsPwned(ctx context.Context, password string) error {
 	if !setting.PasswordCheckPwn {
-		return false, nil
+		return nil
 	}
 
 	client := pwn.New(pwn.WithContext(ctx))
 	count, err := client.CheckPassword(password, true)
 	if err != nil {
-		return true, err
+		return ErrIsPwnedRequest{err}
 	}
 
-	return count > 0, nil
+	if count > 0 {
+		return ErrIsPwned
+	}
+
+	return nil
 }