Refactor devtools mage package in the agent

[kaanyalti]

While working on the following issue/pr, I moved PackageTypes to a new package commonpkg to resolve circular dependency issues. However, this leaves the code in a not so clean state. A cleaner solution would be to move the whole of pkgtypes to its own package (potentially other pkg related files as well). This will require moving other files into their own packages as well as pkgtypes depends on them.