WIP: Seed dev database with massive amount of Projects, Users and Labels

What does this MR do?

Prepares the seed_fu rake task to insert massive amount of records for Users, Projects and Labels. The goal here is:

1. Setting a standard for making these insertions for seed_fu rake, so more people can contribute
2. With these records in place, it'll be easier for catching performance issues during development

TODO

• Populate project.route
• Handle group labels insertion
• Check if there are other seeds iterating on projects and using services for insertion (it doesn't scale)

Closes #28149 (moved)