[ENH] Let user upload an already annotated data dictionary

[surchs]

Is there an existing issue for this?

• I have searched the existing issues

New feature

When I have already used the annotator once to create a neurobagel annotation tool, I would like to be able to use the file I have generated as an input to the annotation tool the next time I use it.

i.e.:

• data dictionary upload accepts neurobagel data dictionary .json
• we parse the neurobagel portion of the user supplied data dictionary
• the app state gets set to reflect the user supplied data dictionary
• inputs get validated: Validate supplied .tsv and .json files #49

Unclear documentation

No response

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[github-actions]

We want to keep our issues up to date and active. This issue hasn't seen any activity in the last 75 days.
We have applied the _flag:stale label to indicate that this issue should be reviewed again.
When you review, please reread the spec and then apply one of these three options:

• prioritize: apply the flag:schedule label to suggest moving this issue into the backlog now
• close: if the issue is no longer relevant, explain why (give others a chance to reply) and then close.
• archive: sometimes an issue has important information or ideas but we won't work on it soon. In this case
  apply the someday label to show that this won't be prioritized. The stalebot will ignore issues with this
  label in the future. Use sparingly!