✨ Add apps, geo, and countries lookup commands (v5 Phase 1)

[SamPetherbridge]

Summary

Phase 1 of #32 — surfaces three read-only lookup resources from the asa-api-client v5 surface that the CLI previously had no way to reach. These are the foundational lookups: you need an app's adamId to create campaigns, and geo ids to target locations.

New commands

Command	Library call	Purpose
asa apps search <query> [--own] [--limit]	client.apps.search	Find advertisable iOS apps and their adamId
asa geo search <query> --country US [--entity] [--limit]	client.geo.search	Find geo locations (Country/AdminArea/Locality) for targeting
asa countries list [--code US ...]	client.countries_or_regions.list	List supported countries/regions and their ad languages

All three support --format table\|json\|csv via the shared output_data helper and follow the existing typer/utils conventions (get_client, spinner, handle_api_error).

Verification

• ✅ ruff check / ruff format --check
• ✅ mypy --strict (16 source files)
• ✅ pytest — 8 passed (added help/registration tests for the 3 new groups)
• ✅ Help renders correctly for each command; full command tree loads

Scope

Part of #32 — does not close it. Remaining phases: creative management (ads, product-pages), reporting & billing (custom-reports, budget-orders), and org/access (acls).