Change the data format of File's creationDate and publishDate from Date to string

[ChengShi-1]

What this PR does / why we need it:

Change the e file creation date and publication date from Date object to string type(as same as the payload format) to avoid a date conflict

Which issue(s) this PR closes:

• Closes Feature Request/Idea: Show a string for the creation date and publication date of file #560

Special notes for your reviewer:

waiting for IQSS/dataverse-client-javascript#226 to be merged.
Once it merged, the package.json should be deleted and not merge into main branch.

Suggestions on how to test this:

• find an existing dataset, or create a new dataset
• upload a file to a dataset, check file deposited date, should be in format 2024-12-16 and correct date
• published the file and check the date in the same place again
  

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

No

Is there a release notes update needed for this change?:

No

Additional documentation:

[coveralls]

coverage: 97.363% (+0.02%) from 97.345%
when pulling 36e6311 on 560-feature-requestidea-show-a-string-for-the-creation-date-and-publication-date-of-file
into 02b04e5 on develop.