Enhances samples functionality with better organization and filtering

[pritamp19]

Reviewers

r? @
cc @stripe/developer-products

This commit addresses the TODO items identified in the samples functionality:

• Add better naming for samples with display_name field
• Implement grouping samples by product categories
• Add comprehensive metadata (difficulty, language, tags)
• Implement advanced filtering capabilities
• Improve display formatting with visual hierarchy

Changes Made

Enhanced SampleData Structure

• Added DisplayName, Category, Tags, Difficulty, and Language fields
• Maintained backward compatibility with sensible defaults
• All new fields are optional

New Helper Functions

• GroupByCategory() - Groups samples by category
• GetCategories() - Returns sorted category list
• FilterByCategory() - Filters by category
• FilterByTag() - Filters by tag
• Safe getters with defaults for all metadata fields

Improved List Command

• Added filtering flags (--category, --difficulty, --language, --tag)
• Added compact display mode (--compact)
• Enhanced help text and usage examples
• Better error handling for filtered results

Visual Improvements

• Category-based organization with emoji icons
• Clear visual separation between groups
• Metadata display when available
• Summary statistics and helpful tips

Backward Compatibility

• All existing functionality preserved
• Original sample names work unchanged
• New fields have sensible defaults
• No breaking changes introduced

Testing

• Comprehensive test coverage for all new functions
• Edge case handling and default value testing
• Filtering functionality validation

Files Modified

• pkg/samples/list.go - Enhanced struct and helper functions
• pkg/cmd/samples/list.go - Improved command with filtering
• pkg/samples/list_test.go - Comprehensive test coverage

Closes #XXX (TODO items in samples functionality)

[cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}