Create project_push_rules table

What does this MR do and why?

Create project_push_rules table as a first step of the plan outlined in One migration to add a new table which will have all the Project push rules included by default. It also fulfils the requirements outlined in #499158 (closed)

References

Screenshots or screen recordings

Before	After

How to set up and validate locally

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #499156