Updated code completion implementation to use CodeCompletionServices class
Updated code completion tests to use CodeCompletionServices
Merge branch 'master' of https://github.com/DynamoDS/Dynamo into fixCompletionTests_Part2
minor fixes
resolved merge conflicts
resolved merge conflicts
Merge branch 'fixCompletionTests_Part3' of https://github.com/aparajit-pratap/Dynamo into fixCompletionTests_Part2
code cleanup
addressed review comments
Merge pull request #2884 from aparajit-pratap/fixCompletionTests_Part2

Updated code block UI and unit tests to use CodeCompletionServices