[Feature]: Allow overriding project.default-distro on the azldev command line

[liunan-ms]

Is your feature request related to a problem? Please describe.
project.default-distro is consumed by several commands as the implicit target when no explicit distro is specified.
For example, in azldev repo query --version <VER>, --version requires project.default-distro.name to be set in project config.

Today the only way to retarget is to mutate azldev.toml, which is awkward when:

• experimenting with a different distro version locally (e.g., azurelinux 4.0 vs 4.1),
• running ad-hoc one-off commands against a different distro,
• driving azldev from CI/scripts that shouldn't have to template the TOML.

Describe the solution you'd like
Add global CLI flags that take precedence over project.default-distro:

--default-distro <name>          # override project.default-distro.name
--default-distro-version <ver>   # override project.default-distro.version

Or

--default-distro name=azurelinux,version=4.0