feat: reverse shares (#86)

* add first concept

* add reverse share funcionality to frontend

* allow creator to limit share expiration

* moved reverse share in seperate module

* add table to manage reverse shares

* delete complete share if reverse share was deleted

* optimize function names

* add db migration

* enable reverse share email notifications

* fix config variable descriptions

* fix migration for new installations

backend/src/config/config.service.ts

@@ -29,6 +29,7 @@ export class ConfigService {
 
   async listForAdmin() {
     return await this.prisma.config.findMany({
+      orderBy: { id: "asc" },
       where: { locked: { equals: false } },
     });
   }