refactor: reorganise code structure to prepare for Snyk OSS integration [ROAD-236]

[michelkaporin]

The code is grouped by product and organised in the following way:

• itly
• snyk
  • common
    Code that will be shared between different product and feature integrations: configuration, analytics, logging, shared view elements, etc.
  • base
    Code that provides base elements for the extension: status bar item, loading badge, welcome web view. Current monolith module is included as it's the entry point to the extension functionality.
  • snykCode
    Code related to Snyk Code product integration, including view and code providers.
  • openSource
    Code related to Snyk Open Source integration. Folder will be added later during dev work on it.

Additionally, this refactoring includes:

• File naming brought to consistency (updated to camelCase)
• BundlesModule refactored and extracted to corresponding SnykCode class with event subscriptions in the Progress class.
• Redundant interfaces removed
• Some interfaces were moved closer to the code that uses them
• Interface naming brought to consistently (start with letter "I").

[pavel-snyk]

Love to see more structure in the plugin, 👍 .

p.s. PR related to ROAD-236, right?

[michelkaporin]

@pavel-snyk thank you. ROAD-236 - that's correct, amended the heading :)