This CL can enable and use the VK_EXT_device_memory_report extension.

This is disabled by default.  To enable, link with the required
extension, enable one or both of two features, AND build with the
following GN arg:

  angle_enable_trace = true

The two added  features are:

- logMemoryReportStats provides per-swap statistics
- logMemoryReportCallbacks provides per-callback logging

If either or both of the features are enabled, if the
VK_EXT_device_memory_report extension is available, it is enabled.

Bug: b/173636655
Change-Id: Ic5cf6c06efdb34f2313ef143853b3cc90f55faa5
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2543506
Commit-Queue: Ian Elliott <ianelliott@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>