feat: Create icon from memory

[sadespresso]

Status

READY

Breaking Changes

NO

Description

• Adds memoryAsset option for enum ShortcutIconAsset
• Adds new helper class ShortcutMemoryIcon that converts Uint8List to base64 string
• Adds Java helper method setIconFromBase64StringCompat for creating icon from base64 formatted jpegs
• Extend Java code to work with the change above
• Bumped version to 1.4.0
• Updated README.md, CHANGELOG.md

This PR closes #18 upon merge

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