Allow clients to access page image information from mobile-html directly without having to go to the summary output.

Strawman proposal

In mobile-html we could add a few meta property tags, like the following:

<meta property="pcs:pageimage:thumb" content="{url: '', width: , }">

Or we could split this up into different properties.
In the PCS abstraction JS layer we could return this data as part of a new data parameter returned by the callback of setMulti() or create a new method for that.