Allow grouping deployment environments at the project level for monorepo

Proposal

At the project level, users can view and manage all their deployment environments.

This becomes challenging for users with a monorepository as they might have different environments (e.g dev, staging, production) for multiple services inside the same project.

This could be solved by grouping deployment environments together per services. For example, having a group "service-a" with a dropdown to see the corresponding environments (service-a-dev, service-a-stagging, service-a-prod).

There are initiatives to improve the environment management at the organisation level but so far this seems to only apply to users with multiple projects and does not solve for monorepo.