feat(oauth): Add option to logout from OpenID Connect provider

* Fixes #598

Signed-off-by: Marvin A. Ruder <signed@mruder.dev>

backend/prisma/migrations/20241007181823_oauth_id_token/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "RefreshToken" ADD COLUMN "oauthIDToken" TEXT;

backend/prisma/schema.prisma

@@ -40,6 +40,8 @@ model RefreshToken {
 
   userId String
   user   User   @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  oauthIDToken  String? // prefixed with the ID of the issuing OAuth provider, separated by a colon
 }
 
 model LoginToken {

backend/prisma/seed/config.seed.ts

@@ -275,6 +275,10 @@ const configVariables: ConfigVariables = {
       type: "string",
       defaultValue: "",
     },
+    "oidc-signOut": {
+      type: "boolean",
+      defaultValue: "false",
+    },
     "oidc-usernameClaim": {
       type: "string",
       defaultValue: "",