Spike: Prepare PoC to introduce scheduled Pipeline Execution Policies

Time-box: 4 days

Why are we doing this work

In the scope of this Spike, we would like to verify what we should do to implement Scheduled Pipeline Execution Policies. We want to allow users to specify a path to custom YAML that needs to be executed in a specified cadence. To avoid further work like Manage scheduled scan execution pipeline concur... (&13997 - closed), we should start with a maximum of one execution of PEP daily for a single project.

As an expected result of this Spike, we would like to get the following:

• PoC MR with proposed changes for backend (GraphQL API, database changes, etc.) or initial plan how to implement it,
• implementation issues for backend and frontend,