Added `waitress` dependency. For performance and security reasons, it's
better to always run the Flask application inside of a uWSGI server.
`waitress` also makes things easier by avoiding to ask the user to
manually provide the external executable arguments, as it was the case
with `uwsgi` and `gunicorn`.
It was broken by the previous refactor of the entities panel, which no
longer triggers the `watch` callback on the upstream `entityGroups`.
The new approach listens for entity updates on the frontend bus and
dynamically creates the entity groupings in `selectedGroups` if they are
missing.
Unlike the other entity groupings, which are 4-layered (`grouping ->
group -> entity_id -> entity`), the grouping by ID only needs 3 layers
(`grouping -> entity_id -> entity`).
- Don't recalculate entity groups every time. Instead, keep them in sync
every time an entity is added or removed.
- Removed `computedChildren` from the entity component - no null nodes
are guaranteed to be passed now, so there's no need for another
iteration on the list of children.
- `childrenByParentId` now only looks in the scope of the entity's
children instead of searching all the entities.
The animation has a big impact on page loading performance when the
system includes a high number of entities that all need their loading
animation to be render.
Multiple style improvements for the entity components. Among these:
- A more consistent style for entity values and toggler buttons.
- Fixed overflowing/underflowing entities on smaller/larger screen
sizes.
- Simplified the stylesheets for many entities as many component classes
have now been moved to `common.scss`.
The entity name and value in the component header may be arbitrarily
long and rendered on small screens.
We therefore need to ensure that the text won't overflow the screen
width.
`entities.transform_entities` will pass back an empty list instead of an
empty dict if no entities were found, and the function should be able to
handle it.