This change updates the source structure of the OpenDC frontend to
follow the page structure.

This change updates the OpenDC frontend to reduce its reliance of global
state during the execution of actions. Actions that modify the topology
now require parameters to be passed via the action constructor instead
of relying on the global interactionLevel state.

This change updates the topology view in the OpenDC frontend to isolate
the world coordinate space. This means that zooming and panning should
not affect the coordinates in world space (but only in camera space). In
turn, this allows us to remove the dependency on Redux for the camera
controls.

This change enables support for panning the visualized datacenter
topology by using the mouse or holding shortcuts. Previously, this could
only be done through repeated key presses.

This change is a rewrite of the existing OpenDC frontend in order to
migrate to the PatternFly 4 design framework.

PatternFly is used by Red Hat for various computing related services such
as OpenShift, Red Hat Virtualization and Cockpit. Since their design
requirements are very similar to those of OpenDC (modeling computing
services), migrating to PatternFly 4 allows us to re-use design choices
from these services.

See https://www.patternfly.org/v4/ for more information about
PatternFly.

This change updates the OpenDC frontend to use the normalizr library for
normalizing the user topology.

This change updates the OpenDC frontend to use React Query for fetching
and mutating project data. Previously, this state was tracked and
synchronized via Redux. Migrating to React Query greatly simplifies the
state synchronization logic necessary in the frontend.

This change removes the current active identifiers from the Redux state.
Instead, we use the router query to track the active project, portfolio
and topology.

This change splits the App container into separate pages, as a starting
point for removing much of the unnecessary state from Redux.