When a notebook is saved/shared for the first time, add the shared ID as a URL parameter on the same page

[agriyakhetarpal]

As stated in the issue title – we want to ensure that if a user reloads the page, they still have their notebook/contents (it currently works but won't after #85).

[agriyakhetarpal]

This will not make sense until #85 is completed, on second thought.

[krassowski]

Discussion:

• for now: work on this rather than Persist the sharing service JWT token across browser sessions #105.
• add ID in the URL
• on open show it as view only

Rationale:

• prevents data loss (e.g. when computer lost power)
• while ensuring another student would be unlikely to modify someone else's notebook