Implement key rotation

[anupama-pathirage]

@tharindu-nw cloned issue wso2-enterprise/ballerina-registry#1602 on 2022-06-01:

Description:

$subject as per the requirements of the internal security audit.

[anupama-pathirage]

@tharindu-nw commented on 2022-06-03:

Choreo cloud team has already planned an implementation of this which can be directly used here as well. However, this implementation is planned around using Azure Key Vault for secrets and credentials. Currently, sealed secrets are used in ballerina central deployments. It was decided to implement the rotation after migrating to Key Vault.

The key vault migration is tracked in https://github.com/wso2-enterprise/ballerina-registry-control-plane/issues/779

Meeting notes can be found at: https://docs.google.com/document/d/13P3Bec1ac_kikNdbEdiOxJZvvAqDQRyd3kXflGsejWk/edit?usp=sharing