refactor(infra): directory structure (#4615)

packages/backend/server/migrations/20230706065816_workspace_subpage/migration.sql

@@ -0,0 +1,12 @@
+/*
+  Warnings:
+
+  - A unique constraint covering the columns `[workspace_id,sub_page_id,entity_id]` on the table `user_workspace_permissions` will be added. If there are existing duplicate values, this will fail.
+
+*/
+-- AlterTable
+ALTER TABLE "user_workspace_permissions" ADD COLUMN     "sub_page_id" VARCHAR,
+ALTER COLUMN "entity_id" DROP NOT NULL;
+
+-- CreateIndex
+CREATE UNIQUE INDEX "user_workspace_permissions_workspace_id_sub_page_id_entity__key" ON "user_workspace_permissions"("workspace_id", "sub_page_id", "entity_id");