Thanks to Jamie Madill for some fixes to get all CI test passing w/ volk.

This change updates all ANGLE targets that use Vulkan to dyanmically
link all of the VK entrypoints using the volk OSS library from
https://github.com/zeux/volk.

It's only two source files so baking them directly into ANGLE repo.
Also it's used in both the tests and libANGLE trees so added to
src/common/third_party/volk dir.

Updated volk and the renderer to track latest instance and device
that were loaded and renderer will refresh vk* function pointers if
the current and previous device and/or instance don't match. This
prevents errors in the test framework as we transition between
backends, especially between VK HW & SwiftShader ICDs.

This change rolls the Vulkan Loader forward to use the latest loader
version which no longer allows static linking but requires dynamic
linking.

Bug: angleproject:3740
Bug: angleproject:4092
Bug: angleproject:4162
Bug: angleproject:4210
Bug: angleproject:4225
Change-Id: I8a0b7d24c9545bbfdfaa4b9357a9bfe6793e0140
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1965640
Commit-Queue: Tobin Ehlis <tobine@google.com>
Reviewed-by: Tobin Ehlis <tobine@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>