Fix rootdirs causing typescript to think non-existent relative paths are ok

[osdiab]

In server and client in order to make typescript not yell about shared not existing i added shared to rootdirs for those packages, but this also means that it thinks that the source of shared is literally accessible through relative paths (it's a virtual src folder that includes both of them)

typescript composite packages, which haven't been released just yet, solve this problem to the best of my knowledge: microsoft/TypeScript#25600

If we use that we can also simplify the publish script for client since only having the real rootDir will cause the dist directory to flatten.