Feat: show system resource usage

[kran6a]

Feature Request

Show overall system resource usage on this section of the TUI.

The resource usage should show how many resources are used by processes managed by process-compose, how many resources are used by other processes and how many resources are available.

Use Case:

Being able to view the aggregated resource usage and capacity without having to use the keyboard to close the TUI, open htop then closing htop and opening the TUI again.

Who Benefits From The Change(s)?

I believe most power users out there would consider it a nice QoL change.

Alternative Approaches

Closing the process-compose TUI, opening htop then closing htop and opening the TUI again.

[F1bonacc1]

Added in v1.34