Add the ProjectId resource identifier class
Merge pull request #259 from sharwell/ProjectId

Add the ProjectId resource identifier class
Add ReadOnlyDictionary class
checkpoint
Support and testing for agent connections
Updated monitoring cleanup test methods
Support and testing for agent tokens
Many updates
More updates
Fix a bunch of build warnings
Simplify DateTimeOffset <-> timestamp conversions with new utility class
Implement many more monitoring methods
Implement remaining monitoring methods
Create specialized NotificationDetails classes for each predefined notification type
Fix method names
Support the created_at, updated_at, and metadata properties for notifications
Updated implementation and tests for notifications and notification plans
Updated notifications tests
Extract method EncodeRequestBodyImpl
Updated traceroute support and tests