[gpu] Make ExportedSharedImage move only

As part of adding GpuMemoryBufferHandle to ExportedSharedImage we add
move only constructors instead of copy constructors to ExportedSI.
This will allow to move the GMBHandle instead of cloning it when
assigning or copying the ExportedSharedImage.

This change adds a Clone method on ExportedSharedImage that allows
current clients of ExportedSharedImage to continue cloning it while
making the ExportedSharedImage mojo move only. This will allow
future usage with GpuMemoryBufferHandle to be moved around.

Bug: 391788839
Change-Id: I8c778a2dd9c326d0c85c349d10ae781e39cafba9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6237513
Reviewed-by: Vasiliy Telezhnikov <vasilyt@chromium.org>
Reviewed-by: Joe Mason <joenotcharles@google.com>
Commit-Queue: vikas soni <vikassoni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1417141}