App Connector Module - Migrate source code from Kyma repo to the module [EPIC]

[koala7659]

We need to migrate following components to be hosted and built directly in application-connector-module repository:

• central-application-connectivity-validator
• central-application-gateway
• compass-runtime-agent (after included into the module) (see App Connector Module - Add Runtime Agent [EPIC]  #48)
• common component

AC:

• Come up with a proposal how the new project layout for the ACM could look, including the sources of the Application Connectivity Validator, Application Gateway and Compass Runtime Agent
  • The new layout should also consider the requirements for the kubebuilder framework
  • Review the proposal with the team and agree on the final layout
• Apply the new layout for the ACM repository
• Migrate all three components (see list in description) into the ACM repository (Migrate the code of old Application Connector code from Kyma repository to ACM repository. #267)
• Ensure unit-tests are correctly working after the components were moved to the ACM repository
• Adjust the security configuration within the ACM repository