[graphite] Consolidate Utils/Types headers

Public headers are consolidated to:
  foo/FooBackendContext.h - holding the backend context and context
     factory
  foo/FooGraphiteTypes.h - holding FooTextureInfo and factories for
     backend textures and semaphores

Minor exceptions are for Metal, which requires the MtlGraphiteTypes
header to be split into an ObjectiveC and C++-only header (this had
been MtlGraphiteUtils.h but I renamed it to emphasize the language
rationale).  Vulkan also uses VulkanGraphiteContext.h since there
is already a shared VulkanBackendContext.h.  When Ganesh goes away,
this can be consolidated.

Internally, the variopus FooGraphiteTypesPriv, FooGraphiteUtilsPriv,
and FooUtilsPriv are consolidated to just FooGraphiteUtils, with impl
moving to FooGraphiteUtils.cpp as well. This is all just code moving
and include updating.

In follow up CLs, the context factory work will be moved out of
FooGraphiteUtils.cpp and into FooContext.cpp. Everything related to
FooTextureSpec will be removed entirely, instead just accessing a
pointer to the public FooTextureInfo using TextureInfoPriv. Lastly,
FooBackendTexture can likely undergo a similar consolidation.

Bug: b/390473370
Change-Id: I242758467cfff3a926e1bafcf5a56c80af15020d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/946258
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
88 files changed