Time Travel: keep active node details panels up-to-date

[fbarl]

Resolves #2776 and implements nicer UX transitions for node details panels when time travelling.

Changes

• Introduces a semitransparent layer in node details panel similar to the one for nodes layout that is activated whenever updating the panel with the data at a different timestamp.
• Each node details panel now has a timestamp attached to it that enables smarter updates.
• Implements a lightweight solution from Time Travel: details panels in the background don't update with timestamp #2776, which triggers the node details panel update every time the top panel is closed and a background one pops into the focus, to make sure the displayed data is always consistent with the timestamp.