Implement capturing glVertexPointer, glTexCoordPointer, glNormalPointer,
glColorPointer and glPointSizePointerOES using a new
CaptureVertexPointerGLES1 helper function.

This is done by using fixed indices for gClientArrays that are retrieved
from the GLES1Renderer.

Bug: angleproject:5751
Change-Id: I6c774ff21942ea3422c4c77a615f88299901c0ab
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2773288Reviewed-by: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Lubosz Sarnecki <lubosz.sarnecki@collabora.com>