Fuzz Corpus Backend technical implementation

This issue to serve as a discussion for backend implementation. After the initial discussion here we will create smaller backend issues/tasks for implementation.

There are two endpoints we can leverage, they are listed here along with existing/missing data for each one.

Existing Package Registry fields to use from Rest endpoint

1. name
2. delete_api_path

Existing Package Registry fields to use from GraphQL Endpoint

1. name
2. pipelines
3. updated_at

Fields to add to Package Registry REST endpoints

1. target
2. pipeline info
3. updated_at
4. last_used

Fields to add to Package Registry GraphQL endpoints

1. target
2. last_used

Existing REST endpoints available:

https://docs.gitlab.com/ee/api/packages.html#list-packages

GraphQL Schema available: