This change updates the project structure to become flattened.
Previously, the simulator, frontend and API each lived into their own
directory.

With this change, all modules of the project live in the top-level
directory of the repository. This should improve discoverability of
modules of the project.

This change adds support for aggregating code coverage results from the
different modules.

This change removes the opendc-core module. This module was an artifact
of the old codebase and remained mostly unused. This change removes all
usages of the module and if necessary introduces replacement classes.

This change moves the bare-metal provisioning packages outside the
compute module since these modules represent different layers in the
ecosystem and should not be mixed.

This change uses the Java Platform functionality from Gradle to enable
shared dependency constraints across modules.

This change updates the Gradle configuration to utilize version
constraints to force the same dependency version across modules.

This change extracts the configuration for test from the Kotlin library
conventions.

This change removes unnecessary dependencies on JUnit Platform launcher
from the repository. Previously, the launcher was used to bootstrap
tests for Gradle when it did not natively support JUnit Platform.

Gradle now has native support for JUnit Platform, so the dependency is
not needed anymore.

This change splits the opendc-compute module into two modules:

  1. opendc-compute-core
     The interfaces and APIs that represent a IaaS platform.
  2. opendc-compute-simulator
     The implementation of these interfaces using simulation components
     from opendc-simulator-compute.