[#17]

Add --limit/-l flag to all list commands for shell scripting composability.

Changes

Added --limit flag to:

• apps list
• alerts policies list
• dashboards list
• users list
• synthetics list
• logs rules list

Notes on Issue #17

This PR partially addresses #17:

--limit flag (completed):

• Added to all list commands that were missing it
• deployments list and deployments search already had --limit

--force flag (already complete / N/A):

• logs rules delete already has --force implemented
• Delete commands for dashboards, deployments, and synthetics don't exist yet in the codebase

Test Plan

• Build passes: make build
• Tests pass: make test
• Verify --limit flag appears in help: ./newrelic-cli apps list --help
• Test limit truncation: ./newrelic-cli apps list --limit 1