Use sharing token from URL for sharing links if it exists

[philippotto]

URL of deployed dev instance (used for testing):

• https://reuseurltokenforsharing.webknossos.xyz/

Steps to test:

• open a private dataset
• create a sharing link (A)
• open that link in an incognito window
• click the share button -> the copied url should contain the same token as in (A)

Issues:

• see https://scm.slack.com/archives/C5AKLAV0B/p1660204300742279?thread_ts=1660202133.556449&cid=C5AKLAV0B

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(Please delete unneeded items, merge only when none are left open)

• Updated (unreleased) changelog
• Updated (unreleased) migration guide if applicable
• Updated documentation if applicable
• Adapted wk-connect if datastore API changes
• Adapted wk-libs python client if relevant API parts change
• Needs datastore update after deployment
• Ready for review

[daniel-wer]

Hmm, did this work for you during testing? For me, the copied link in the incognito tab doesn't contain a token, neither for a shared dataset nor for an annotation.

[philippotto]

Hmm, did this work for you during testing? For me, the copied link in the incognito tab doesn't contain a token, neither for a shared dataset nor for an annotation.

Sorry for the trouble! It worked for me when I opened the PR, but apparently I must have been logged in when I tried to acquire the link. Maybe I didn't use incognito or I was already logged-in in my incognito session (since chrome only supports one incognito session at the same time).

Now it should work :)

[daniel-wer]

Works like a charm now 👍