show client time when script and lesson edit pages are saved

[davidsbailey]

Finishes PLAT-668.

before (levelbuilder):

before (localhost):

after (localhost):

Testing story

Manually verified that the last saved timestamp matches my local system clock time on the script edit page and lesson edit page.

Reviewer Checklist:

• Tests provide adequate coverage
• Privacy and Security impacts have been assessed
• Code is well-commented
• New features are translatable or updates will not break translations
• Relevant documentation has been added or updated
• User impact is well-understood and desirable
• Pull Request is labeled appropriately
• Follow-up work items (including potential tech debt) are tracked and linked

[davidsbailey]

apologies, I sent this too soon. I will mention you both again when tests are passing.

[dmcavoy]

I added updatedAt to the summarize methods for Script and Lesson to make this work. I think this means we don't need that information in the summarize anymore.

It should be removed from the following places:

https://github.com/code-dot-org/code-dot-org/blob/staging/dashboard/app/models/script.rb#L1352
https://github.com/code-dot-org/code-dot-org/blob/staging/dashboard/app/models/lesson.rb#L308
https://github.com/code-dot-org/code-dot-org/blob/staging/dashboard/app/controllers/lessons_controller.rb#L37
https://github.com/code-dot-org/code-dot-org/blob/staging/apps/src/lib/levelbuilder/lesson-editor/LessonEditor.jsx#L92
https://github.com/code-dot-org/code-dot-org/blob/staging/apps/test/unit/lib/levelbuilder/script-editor/ScriptEditorTest.jsx#L197
https://github.com/code-dot-org/code-dot-org/blob/staging/apps/test/unit/lib/levelbuilder/script-editor/ScriptEditorTest.jsx#L271

If you want me to follow up with that work let me know.

[davidsbailey]

@dmcavoy @bethanyaconnor this is ready for review now. Dani, thanks for the pointers to updatedAt. I just went and removed them in this PR.

[dmcavoy]

Cool! TIL :)

[dmcavoy]

Thanks for following up and cleaning up all those places where updatedAt was!