Make API calls with time travel timestamp

[fbarl]

Fixes #2609. Now we (hopefully) only need to adress #2608 before removing the feature flag.

Changes

• Node details now display timestamps relative to the ttime we jumped to with the Time Travel control.
• List of topologies as well as topology stats also change when travelling in time.
• Modified the overlay displayed when jumping in time so that it affects the whole rest of the screen (with node details and topologies lists) and not just the rendered nodes.
• Improved the empty state messaging for the resource view, as it became more important with time travelling.

Pain points

• Would be nice to update the timestamps in Node Details every second, e.g. by wrapping them in some sort of <AutoRefreshable /> component.
• A lot of selectors/actions logic is becoming unnecessarily complicated because Resource View is an exception to a lot of things, drawing its displayed nodes from nodesByTopology global state instead of nodes - would be nice to unify these two global states into one.

[2opremio]

Backend code LGTM (modulo minor naming nits)

[jpellizzari]

LGTM! Only one question about Go error handling. I am assuming we are going to do another iteration on the UI design for time travel? The feature itself is not very prominent, but I can save that feedback if we are doing another round of changes.

[fbarl]

I am assuming we are going to do another iteration on the UI design for time travel?

@jpellizzari Yes! #2608 is the design follow-up issue, thanks for reminding me to reference it here.