add the ability to resolve users and parents

[johguentner]

• some entities have parents or expose user-ids, without additional information
• by resolving these within the "endpoint" (not a real notion enpoint) Resolve::class, the additional information can be easily obtained

[what-the-diff]

• Added a new endpoint for comments
• Added the ability to resolve users, pages and databases from notion parents (e.g.: blocks)
• Add timestamps, archive status and parent information to block entities
• Add comment entity with collection class
• Added HasTimestamps, HasArchive and HasParent traits to Database entity
• Removed createdTime and lastEditedTime properties from Database entity
• Moved fillId() method from Entity class to NotionParent class (which is a parent of all entities)
• Renamed fillCreatedTime(), fillLastEditedTime() methods in Page, Block classes as they are now handled by the trait added in step 1 above
• Changed signature of setResponseData(array $responseData): void method on PropertyItem interface so that it throws HandlingException instead of \InvalidArgumentException exception when invalid data is passed into it
• Added comments endpoint
• Added resolve endpoint
• Refactored blocks to use new traits for timestamps, parent and archive attributes
• Added new properties to Database entity
• Added new property to Page entity
• Fixed typo in User Entity (object_type)
• Updated specific block response with archived and parent data, added paragraph test text
• Created comments endpoints tests for create comment and list comments: 403 error responses, 404 error responses, 200 success responses

[mechelon]

For v1.1.0 👍

[johguentner]

@mechelon: Regarding review - you don't have to check all files (most of the changes come from other open PRs); Please check the tests and the according Notion workspace. If you need anything, please let me know :)