Gets the list of data providers of a Web Intelligence document.
GET <webiURL>/documents/{documentId}/dataproviders
Response type: application/xml or application/json
Response body: the list of <dataprovider> elements with the following information:
GET <webiURL>/documents/7738/dataproviders
<dataproviders> <dataprovider> <id>DP0</id> <name>Query 1</name> <updated>2006-09-20Z</updated> </dataprovider> <dataprovider> ... </dataprovider> </dataproviders>