Add help tips metadata

[#54519202]
Validate help tips, implement help system skeleton and use it

[#54519202]
Add help system icon in the top-left corner

[#54519202]
Automatically wrap markdown content in div.markdown-typography

[#54519202]
Implement Lab help system

[#54519202]
Update "Tooltips" interactive so now it presents helptips too

[#54519202]
AWS server creation: fix args to new_dns_record
Make logAction an ExportController class method

This makes it available, for example, to the sensor model (which has no notion of DataGames, nor of the exportController *instance*, which is controlled by the interactive controller.)

IS [#48363865]
log sensor and device disconnects

IS [#48363865]
Link to launch NextGen model in DG staging server

IS [#54388024]
add ITSI curricular category w/3 Interactives

[#54648794]
Fix for shape tests that might work
additional fixes for testing shapes
add another hack to interactive serialization

FIXME:
This fixes the failing interactive serialization mocha
tests … but we need something more robust.

helpTips have a defaultValue of an empty array … but
they are not required as part of the JSON form for an
interactive.

But when we check to make sure that the serialization of
an instantiated interactive matches the original JSON
without this hack helpTips is added … and the serialized
JSON doesn't match the original.
use xProperty 'time' for energy2d linegraphs

The graph can't handle the format produced by displayTime
in energy2d yet.
Lab help: let user sequence backward, add keyboard handlers

[#54519202]
Let author specify help tip for model container

[#54519202]
Simplify helptips serialization, they can't be undefined

as their default value is [].
Add margin to help tips, so they never touch interactive boundaries

[#54519202]
Add cookies.js module with cookies helper adapted from MDN pages

[#54519202]