Fetch and use thumbnail across the app

[maskaravivek]

Description (required)

Why we are replacing MediaWikiImageView (which extends SimpleDraweeView) with SimpleDraweeView?

• MediaWikiImageView takes a filename and does an API call to fetch its thumbnail using an API call ie findThumbnailByFilename and then maintains a filename to thumbnail URL cache.

As the behavior of fetching the thumbnail was part of the view itself, the thumbnail is fetched every time the view is rendered(if not already in the cache). That results in an extra API call being made for every single image.

Now, as the app is consuming the imageinfo API, we already have the thumbnail URL for most of the images ie explore, search, POTD and media detail. Only contribution list doesn't have thumbnail as of now. If we implement #2904, even the contribution list will have thumbnail beforehand. Until then contribution view holder can fetch and display the thumbnail.

Fixes #2898

How?

Earlier MediaWikiImageView was used in media detail and as per the behaviour of MediaWikiImageView, it was showing thumbnails.

Fixes #2820

How?

The change in appendMediaProperties automatically gets 640 width thumbs for all media. This is in addition to the original url.

Fixes #2907

How?

Using Fresco's image controller, we are loading low and res images to a simple drawee view.

[maskaravivek]

This can be removed once #2904 is in place.