feat(shorebird_cli): shorebird --version checks for updates

[felangel]

Description

• feat(shorebird_cli): shorebird --version checks for updates (closes fix: shorebird --version does not notify that newer versions are available #483)

Type of Change

• ✨ New feature (non-breaking change which adds functionality)
• 🛠️ Bug fix (non-breaking change which fixes an issue)
• ❌ Breaking change (fix or feature that would cause existing functionality to change)
• 🧹 Code refactor
• ✅ Build configuration change
• 📝 Documentation
• 🗑️ Chore

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (2e03f96) 100.00% compared to head (a240953) 100.00%.

Additional details and impacted files

@@            Coverage Diff            @@
##              main     #1499   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          150       150           
  Lines         4665      4669    +4     
=========================================
+ Hits          4665      4669    +4     

Flag	Coverage Δ
shorebird_cli	100.00% <100.00%> (ø)

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