Make use of shareable promise images in tools

The main change here is just fusing the following three methods into recreateSKP:
   deflateSKP
   createCallbackContexts
   createSKP

All the remaining changes are just API fallout from that.

Bug: skia:11728
Change-Id: Iae2ce65983ad56c8288bdc830e248394a0055bfb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/389925
Reviewed-by: Adlai Holler <adlai@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
7 files changed