Backend API for CPU/Memory Usage

### Epic

#223

### Description

**As a:** project owner

**I want to:** know my projects CPU and Memory use over the last 24hrs/7days/30days

**So that:** I can judge if I need to upgrade to a higher capacity project type

### Acceptance Criteria

- [ ] Capture data for Docker, K8S and possibly local fs instances
- [ ] Record data points with appropriate granularity
- [ ] API to supply data to front end
- ...