* chore move sql_execution_context to sqllab package
* add new helper methods into base Dao
* refactor separate get existing query concern from command
* refactor separate query access validation concern
* refactor separate get query's database concern from command
* refactor separate get query rendering concern from command
* refactor sqllab_execution_context
* refactor separate creating payload for view
* chore decouple command from superset app
* fix pylint issues
* fix failed tests
* fix pylint issues
* fix failed test
* fix failed black
* fix failed black
* fix failed test
* allow csv upload to accept parquet file
* fix mypy
* fix if statement
* add test for specificying columns in CSV upload
* clean up test
* change order in test
* fix failures
* upload parquet to seperate table in test
* fix error message
* fix mypy again
* rename other extensions to columnar
* add new form for columnar upload
* add support for zip files
* undo csv form changes except usecols
* add more tests for zip
* isort & black
* pylint
* fix trailing space
* address more review comments
* pylint
* black
* resolve remaining issues