Fix handling of PyDev debug server ports

This resolves the issue of (within workflow) failing to connect
the Python Pydev actor to the debug server
Added locking for file readers.
Fixup for moving Python RPC into its own bundle
Merge Fixes to Python RPC moving around
DAWNSCI-736: Add helper to filter and format remote exceptions
Merge branch 'master' of github.com:DawnScience/dawn-common
Merge branch 'master' into actorv5