feat(dart_frog): add tryRead method to RequestContext

[mtwichel]

Status

READY

Description

Closes #1651. Adds a tryRead function to the RequestContext that works exactly like read, but instead of throwing a StateError when a provided value isn't found, it return null. This is useful for objects that may or not be provided depending on certain factors, like a User being provided only if they are authenticated. The change has also been reflected in the docs site.

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