This change moves the OpenDC modules previously living in the simulator/opendc
directory to the simulator directory itself given that we do not make a
distinction between OpenDC and odcsim anymore.

This change removes the odcsim components from the repository as we have
eliminated their use in the OpenDC codebase, by replacing them with the
more generic (Test)CoroutineScope and Clock. From now on, we will only
place modules under the OpenDC namespace and not use odcsim as well to
prevent confusion.

This change updates the code base to use Kotlin 1.4 which promises
better performance in IDEs and a new interference algorithm to solve
more complex type checking cases.

See https://kotlinlang.org/docs/reference/whatsnew14.html for more
information.

This change prepares the simulator Git repository for the monorepo residing at
https://github.com/atlarge-research.com/opendc. To accomodate for this, we
move all files into a simulator subdirectory.