Repository Restructuring

• Library source code is moved to the src/evidently folder
• Docs, Tests, and Examples are moved to the top level of the repo
• Widgets and Tabs are moved inside of the src/evidently/dashboard folder, as those are parts of the Dashboard
• Sections are moved inside of the src/evidently/model_profile folder, as those are parts of the Model_profiles
• Docs are stored in the repo: docs/book folder
• DataDriftAnalyzer refactoring: analyzer results became a structured object instead of a dictionary