Rename webapi-sampleapp-embedding-tests to embeddingapi-usecase-tests

See requirement at pull request #769 comments
[webapi][xwalk-2309] Use launch instead of AppControl to throw WebAPIException

- AppControl is not supported in Crosswalk at now. Use launch() instead to throw WebAPIException.
- Fail Reason: Const attributes are not implemented(XWALK-2309); Wrong exception thrown(XWALK-1659); Error message is a empty string, no message info.

Impacted tests(approved): new 0, update 35, delete 0
Unit test platform: [Tizen IVI]
Unit test result summary: pass 6, fail 27, block 0
Merge pull request #772 from haoxli/haoxli/webapi/update-tizen-tests

[webapi][xwalk-2309] Use launch instead of AppControl to throw WebAPIException