Bug fix: For a javascript ajax call, set the return code instead of default 200 in error view exception handler

[liyaqin1]

Customer reported a bug: https://jira.pinadmin.com/browse/CDP-8039

[gzpcho]

Would be good to see if we can address the TODO on this fie:

teletraan/deploy-board/deploy_board/webapp/error_views.py

Lines 26 to 29 in d9675f8

	# TODO so we are using this as the catch ALL, and report error, as the last resort
	# this is fine, except the exception stack trace is not particularly user-friendly
	# We should not depends on this too much, but in the code handle as much exception
	# as we can and generate user friendly message there.