[Fontations] Support makeClone() for variations

Implement makeClone() based on makeFromStream/Data
implementations. Modify SkTypeface_Fontations constructor to accept
SkData instead of stream. Perform stream to data wrapping in
MakeFromStream function.

Modify test case to exercise makeClone() code path.

Bug: skia:14361
Change-Id: Ic87828fe25a3f983c243e527abba87e5acda6447
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/708596
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Dominik Röttsches <drott@google.com>
3 files changed