feat: support webauthn login (#4945)

* feat: support webauthn login

* manually merge

* fix: clear user cache after updating authn

* decrease db size of Authn

* change authn type to text

* simplify code structure

---------

Co-authored-by: Andy Hsu <i@nn.ci>

internal/authn/authn.go

@@ -0,0 +1,25 @@
+package authn
+
+import (
+	"net/http"
+	"net/url"
+
+	"github.com/alist-org/alist/v3/internal/conf"
+	"github.com/alist-org/alist/v3/internal/setting"
+	"github.com/alist-org/alist/v3/server/common"
+	"github.com/go-webauthn/webauthn/webauthn"
+)
+
+func NewAuthnInstance(r *http.Request) (*webauthn.WebAuthn, error) {
+	siteUrl, err := url.Parse(common.GetApiUrl(r))
+	if err != nil {
+		return nil, err
+	}
+	return webauthn.New(&webauthn.Config{
+		RPDisplayName: setting.GetStr(conf.SiteTitle),
+		RPID:          siteUrl.Hostname(),
+		//RPOrigin:      siteUrl.String(),
+		RPOrigins: []string{siteUrl.String()},
+		// RPOrigin: "http://localhost:5173"
+	})
+}