Automate creation of test projects for security products

When use following guidelines for creation of test projects,

https://gitlab.com/gitlab-org/security-products/tests/common/

Regardless of programming language there are common steps for setting up test projects. (i.e creating different branches, configuring webhook for slack etc). We could write script to automate these common steps when creating new test project. Script could also go through existing projects and update missing steps (i.e go through repos and add auto-devops-FREEZE branch from master and removes the .gitlab-ci.yml file in case it has not been done yet)

p.s feel free to edit this issue and add more details in case it is needed.