use find and remove unneccessary checks

extensions/ql-vscode/src/databases/config/db-config-store.ts

@@ -114,11 +114,14 @@ export class DbConfigStore extends DisposableObject {
 
     const config: DbConfig = cloneDbConfig(this.config);
     if (parentList) {
-      config.databases.remote.repositoryLists.forEach((list) => {
-        if (list.name === parentList) {
-          list.repositories.push(repoNwo);
+      const parent = config.databases.remote.repositoryLists.find(
+        (list) => list.name === parentList,
+      );
+      if (!parent) {
+        throw Error(`Cannot find parent list '${parentList}'`);
+      } else {
+        parent.repositories.push(repoNwo);
       }
-      });
     } else {
       config.databases.remote.repositories.push(repoNwo);
     }

extensions/ql-vscode/src/databases/db-manager.ts

@@ -79,13 +79,6 @@ export class DbManager {
     nwo: string,
     parentList?: string,
   ): Promise<void> {
-    if (nwo === "") {
-      throw new Error("Repository name cannot be empty");
-    }
-    if (this.dbConfigStore.doesRemoteDbExist(nwo)) {
-      throw new Error(`The repository '${nwo}' already exists`);
-    }
-
     await this.dbConfigStore.addRemoteRepo(nwo, parentList);
   }