providers/saml: Metadata Import (#432)

* providers/saml: add basic metadata parser

* providers/saml: add importer for Singing certificate, validate signature, add tests

* providers/saml: add provider name to form,

* web: don't use trailing slash for spa URLs

* providers/saml: formatting fixes

* sources/*: add verbose_name to source serializers

* admin: add button launch import modal

web/src/pages/applications/ApplicationListPage.ts

@@ -9,7 +9,7 @@ import "../../elements/buttons/SpinnerButton";
 import { TableColumn } from "../../elements/table/Table";
 
 @customElement("ak-application-list")
-export class ApplicationList extends TablePage<Application> {
+export class ApplicationListPage extends TablePage<Application> {
     searchEnabled(): boolean {
         return true;
     }