The blitter has a cache which can allow us to reuse already used
routines, so it should be kept in a central location. For that
reason, the blitter ownership was moved from the Image object to
the Device object.

Bug b/117974925

Change-Id: I825853c381dcbc04701b1d9e7dfa376108294221
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/25728Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>