[Request]: Storage - Add configuration for default container disk capacity

### Feature or enhancement request details

Allow configuring the default disk capacity for native containers (and optionally for builder), similar to how CPU and memory defaults are set. The current default (512 GB) can be limiting for large builds or data-heavy workloads; enabling configurable defaults would let users define higher storage limits globally without passing `--storage` on every run.

Example usage:
```
container system property set rootfs.capacity --default-storage=1TB
container run --storage=512GB myimage
```

Some things to consider:
* Extend configuration management to include default disk capacity.
* Apply defaults consistently across native, and builder containers.
* Validate user specified capacity against host available space.
* Surface current defaults via container config list or system info.

### Code of Conduct

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