AWS RDS connection via SSM and SecretsManager

[Arlington1985]

Is your feature request related to a problem? Please describe.
It seems there is no any solution yet developed to be able to connect to AWS RDS database when it's located in private subnet and only ssm connection is allowed also the user password is stored in AWS Secrets Manager which regularly rotated.

Describe the solution you'd like
Easier way of configuration to be able to specify instance_id and secret arn and other AWS connection parameters to be able to connect RDS instance described in upper section

Describe alternatives you've considered
Right now, the only alternative is open tunnel to RDS using aws ssm cli command and regularly update password manually by after getting it from secrets manager

Additional context
I am not sure if it's good to create new plugin or easier just add it as functionality for example to MySQL official plugin as feature but it's very much needed which also wanted in different tools. For example: aws/aws-toolkit-vscode#1914