Pipeline view of manual environments

Problem

The current list view of environments does not convey a flow from one environment to the next.

Also, this might make it possible to display comparison information and status data across environments more easily

Proposal

Create a pipeline view for environments similar to this.

We will create a list view that displays essentially the same information as our existing environments list view, but focusses in on only normal environments.

Display of environment will be based on .gitlab-ci.yml info (stages, manual actions etc)

We can later on improve this view with additional data such commits, merge requests, pod health etc..

See for a schema example:

┌───────────────────────────────────────┐         ┌───────────────────────────────────────┐
│         Stage name (staging)          │         │        Stage name (Production)        │
│                                       │         │                                       │
└───────────────────────────────────────┘         └───────────────────────────────────────┘
┌───────────────────────────────────────┐         ┌───────────────────────────────────────┐
│                       ┌─────────────┐ │         │                                       │
│                       │Manual action│─┼───┐     │                                       │
│                       └─────────────┘ │   │     │                                       │
│                                       │   │     │                                       │
│                                       │   │     │                                       │
│              Environment              │   │     │              Environment              │
│                                       │   ├────▶│                                       │
│                                       │   │     │                                       │
│                                       │   │     │                                       │
│                                       │   │     │                                       │
│                                       │   │     │                                       │
│                                       │   │     │                                       │
└───────────────────────────────────────┘   │     └───────────────────────────────────────┘
                                            │     ┌───────────────────────────────────────┐
                                            │     │                                       │
                                            │     │                                       │
                                            │     │                                       │
                                            │     │                                       │
                                            │     │                                       │
                                            │     │              Environment              │
                                            └────▶│                                       │
                                                  │                                       │
                                                  │                                       │
                                                  │                                       │
                                                  │                                       │
                                                  │                                       │
                                                  └───────────────────────────────────────┘