* Keep status code and response in memory
* Allow external cache preloading.
This will be required for the one-stop mathoid batch rendering
* Duplicate functionality from the restBASE interface
** Error rendering
** Validity checks
** getter for validated tex
Depends-On: Ic779e671ada0d0306e0935e578b47c431abd520e
Change-Id: I066975b9ba03f5861f6c92687cba4743044ea82a
Use WANObjectCache rather than genuine DB tables for greater
flexibility.
Note, this commit is the second step of Ifd89e2d9cb30fa15cc318f077b434207ed6b7214
Bug: T252390
Change-Id: Ifa7d943875f05088ef697a5a18ad292342a9b4ad