Feature: Support stubs in Ghidra Import script

[jonschz]

• Make the Ghidra import script import names, addresses and call type for stubs instead of ignoring them
• Don't import arguments, as we will lose Ghidra's automatic argument detection otherwise
• Consider adding a note/comment in Ghidra that this function is a stub, and auto-remove / change that when the stub is changed to a function

based on #909 (comment)