fix: add default localizations

[Kirpal]

Description

I added default widgets/material/cupertino localizations so the user doesn't need to manually add them, but they can if they want to.

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

Merging #68 (e43b28a) into main (f9f57c9) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##              main       #68   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           13        13           
  Lines          518       538   +20     
=========================================
+ Hits           518       538   +20     

Impacted Files	Coverage Δ
lib/src/golden_test_adapter.dart	100.00% <100.00%> (ø)

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