feat: add tenant api to create tenant resources for cloud

[Kaitou786]

Adding the initial version of the tenant API
This is based on a POST request and the cloud specified does the following:

• Generates a random password for the database and encrypts it using sops with the specified
• Creates all the required tenant resources; HelmRelease, namespace, secret
• add the tenant in the specific location and add its entry into kustomization.yaml
• creates a commit for it
• send an automated PR to update the aws-sandbox repository

Test Plan:

Tested locally by passing the config file with correct credentials and things with the example tenant present on this diff.

see the opened diffs: https://github.com/flanksource/aws-sandbox/pull/166

closes #1