Plumbing to make ANGLE use VK_EXT_line_rasterization
extension when available.

Bug: angleproject:3981
Change-Id: I12913c20bff69ab0b7c16462c10b8b5fd8e1c2a5
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1865027Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Alexis Hétu <sugoi@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>