Accept serialized Tale in POST /tale/import

[Xarthisius]

This PR enables importing serialized Tales via POST /tale/import

How to test

1. Create a Tale and add something to the workspace.
2. Export the Tale (both formats)
3. Remove the Tale
4. Try to upload a zip file

curl -X POST \
  --header 'Content-Type: application/zip' \
  --header 'Accept: application/json' \
  --header 'Girder-Token: ...' \
  --data-binary "@/path/to/tale.zip" \
  'https://girder.local.wholetale.org/api/v1/tale/import?imageId=5a563172a415f100018b9c38&url=https%3A%2F%2Fgoogle.com%2F&spawn=false'

[codecov]

Codecov Report

Merging #259 into master will increase coverage by 0.01%.
The diff coverage is 88.98%.

@@            Coverage Diff             @@
##           master     #259      +/-   ##
==========================================
+ Coverage   87.51%   87.52%   +0.01%     
==========================================
  Files          41       42       +1     
  Lines        2563     2670     +107     
==========================================
+ Hits         2243     2337      +94     
- Misses        320      333      +13

Impacted Files	Coverage Δ
server/rest/tale.py	94.69% <82.97%> (-3.21%)	⬇️
server/tasks/import_tale.py	92.95% <92.95%> (ø)

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[ThomasThelen]

Pretty awesome. I followed your testing steps and got the Tale back with the workspace. One note that is that I used https in the curl request (http will give Temporary Redirect).

[craig-willis]

That did it.