CLI for introspecting memory usage from the terminal

## Brief feature description

Make it possible to fetch statistics related to memory usage of an `iox2` system from the CLI

## Detailed information

Nice to haves:
1. Memory usage of allocated memory per-service (max samples, used samples)
2. Memory usage of entire `iox2` system (how many storages? what size are they and how much is in use?)

Start by locating the existing iox2 CLI entry point and the memory and storage reporting surfaces. Define how the CLI should expose per-service allocation statistics and whole-system storage counts, sizes, and usage. Done means the agreed statistics are available from the terminal with validated output and coverage for the supported cases.

Written by the indexing model from the issue text.