request: `azldev comp show-spec`: read-only spec viewing

[reubeno]

Pain point: To inspect an upstream spec before adding overlays, you currently need to:

1. Add a bare [components.<name>] entry to components.toml
2. Run azldev comp prep-sources -p <name> --skip-overlays -o /tmp/inspect
3. Read the spec
4. Remove the temp entry

A dedicated read-only command would eliminate steps 1 and 4.

Proposed: azldev comp show-spec -p <name> — fetches and displays the upstream spec without requiring the component to be registered. Could also support --upstream-distro and --upstream-version flags.

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Imported on behalf of @dmcilvaney