Handle empty namespaces in import

[scottbell]

Closes #7617

Describe your changes:

When importing a JSON dump that came from a setup without a namespace set, the regex we use in the ImportJsonAction was setting the key to namespace:key, instead of properly separating the two. Now we detect corrupted keys, and repair them during the import.

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[codecov]

Codecov Report

Attention: Patch coverage is 90.90909% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 56.14%. Comparing base (e305b46) to head (f172401).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #7619      +/-   ##
==========================================
- Coverage   56.15%   56.14%   -0.01%     
==========================================
  Files         672      672              
  Lines       27122    27128       +6     
  Branches     2635     2635              
==========================================
+ Hits        15230    15231       +1     
- Misses      11565    11570       +5     
  Partials      327      327              

Flag	Coverage Δ
e2e-full	23.57% <0.00%> (-0.02%)	⬇️
e2e-stable	59.90% <0.00%> (-0.08%)	⬇️
unit	49.11% <90.90%> (+0.01%)	⬆️

Files	Coverage Δ
...ugins/importFromJSONAction/ImportFromJSONAction.js	68.31% <90.90%> (+3.05%)	⬆️

... and 4 files with indirect coverage changes

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[scottbell]

This is pretty tricky to write an e2e test because we need to test with a namespace'd couchdb server, which I don't think we have.

[ozyx]

Looks good! Just needs some kind of test

[akhenry]

Tested locally and it looks good. Filed a followup for the test - #7621

[scottbell]

Tested locally and it looks good. Filed a followup for the test - #7621

@akhenry Added a test to this PR FWIW

[akhenry]

Tested locally and it looks good. Filed a followup for the test - #7621

@akhenry Added a test to this PR FWIW

Then I'll go ahead and close the followup :) Thanks!