Fix zero feature count display in layer summaries

[danmaps]

Motivation

• Ensure layers with an explicit 0 feature count are shown as 0 instead of - by distinguishing None from falsy values.

Description

• Update display logic in cli/arcgispro_cli/commands/query.py and cli/arcgispro_cli/commands/inspect.py to use feature_count = layer.get("featureCount") and format with f"{feature_count:,}" when feature_count is not None, otherwise show "-".

Testing

• No automated tests were run for this change; the edits are limited to presentation logic in two CLI output locations.

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Codex Task