[CredentialManagement] Import Credential Management Web Platform Tests

[CredentialManagement] Import Credential Management Web Platform Tests
https://bugs.webkit.org/show_bug.cgi?id=172015
<rdar://problem/36083577>

Reviewed by Youenn Fablet.

* resources/import-expectations.json:
* web-platform-tests/credential-management/credentialscontainer-create-basics.https-expected.txt: Added.
* web-platform-tests/credential-management/credentialscontainer-create-basics.https.html: Added.
* web-platform-tests/credential-management/idl.https-expected.txt: Added.
* web-platform-tests/credential-management/idl.https.html: Added.
* web-platform-tests/credential-management/w3c-import.log: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@226001 268f45cc-cd09-0410-ab3c-d52691b4dbfc