Renaming things for consistency: DataProvider -> Provider

Change-Id: Ia1f022baef02b477296c9664e7280c75b1c84515
Replace old API code with providers + fix a few provider bugs

Mingle: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/123
Change-Id: Id7952f0a0eafa34d7c8691c63c2daccff2eea64a
Add provider to for actual image loading

Change-Id: I9ca9bce37c97648afa07db9f004138a791c74e65
Mingle: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/123
Merge "Renaming things for consistency: DataProvider -> Provider"
Merge "Replace old API code with providers + fix a few provider bugs"
Merge "Add provider to for actual image loading"