[#46870781] Slick-grid used in CSV import dialog
Fixes styleguide instance->datasource rename bug
[#46870781] WIP: Replace column headers with input boxes
[#46870781] Style CSV import data table after switch to SlickGrid
[#46870781] Update references to match new Slick Grid DOM structure
[#46870781] Extract ImportDataGridView from NewTableImportCSV dialog and use it in the ExistingTableImportCSVDialog.
Merge branch 'master' of github.com:GreenplumChorus/chorus

Conflicts:
	app/assets/stylesheets/dataset/_dataset_table_import.scss
[#46424639] Don't try to show a toast message with dataSource.name when dataSource is undefined
Merge branch 'master' of github.com:GreenplumChorus/chorus