make deployment idempotent

[contrun]

While was deploying this program to aws, I encountered an error as I did not setup sufficient permission. When I deploy the second time, I encountered various deploy error like

 Serverless Error ---------------------------------------

  An error occurred: IamRoleLambdaExecution - bitwarden-serverless-prod-us-east-1-lambdaRole already exists.

and

 Serverless Error ---------------------------------------

  An error occurred: FoldersTable - bitwarden-serverless-prod-folders already exists.

I have to delete the all the tables and roles before continue. Is it possible to check if bitwarden-serverless-prod-folders is empty before directly aborting the deployment? The deployment process should be idempotent.

[vvondra]

I think this is a limitation of serverless framework itself. Maybe somehow need to configure it better.

I'm happy for any contributions here.