Implement extensibility for alpha module command group

[kwiatekus]

Description

Allow modules to bring custom configurability for their Module CRs
For example:

• allow exposing docker registry via CLI
  kyma alpha module configure docker-registry --external-access --storage ....
kyma alpha module add docker-registry --external-access --storage ....
• defining default runtime profile for serverless via CLI

AC

• configuration options are detected based on configmap installed as part of module operator resources
• Adding custom patches for existing module CRs should be possible
• Adding custom patches should be possible also when calling add command
• Add a config map extension for docker registry allowing to pass options for exposing docker registry (as a working example that proves the concept)

Execution

• implement mechanism to detect config maps and build new commands based on their definitions
• define config map in docker-registry operator resources

Reasons

Configuration for module CRs via CLI is much more convenient then editing Module CR via kubectl edit

Attachments

#2221 (comment)