change resource state import from CodeAction to CompletionItem with t…

[Zee2413]

…abstop placeholders

Description of changes:

• change the resource state insertion from CodeAction to CompletionItem
• values required user input have tab stops with placeholder text such as:
  • write only required property for LambdaFunction1
• primary identifiers no longer require user input
  • i.e., no placeholder for BucketName when cloning AWS::S3::Bucket
• using EditorSettings for indentation instead of previously hardcoded indentation of '2'
• insertion of text on client side is changing from workspace.applyEdit() to SnippetString which applies auto indentation and supports tabstops
  • this necessitated many formatting changes in server side

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