Add test for array of arrays of samplers
Add test for array of arrays of samplers

This test fails on the Vulkan backend because Vulkan does not allow
arrays of arrays of samplers.

Also adds a few other tests relating to arrays of arrays.

Test: ./angle_end2end_tests --gtest_filter='GLSLTest_ES31.*'
Bug: angleproject:3604
Change-Id: I5c47119b6ba6d26fe30fdd9c6730caac6f222696
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1733476
Commit-Queue: James Dong <0f4244c6d107216fb8af42c00ad62215f66cb2f9@google.com>
Reviewed-by: Shahbaz Youssefi <582eeec4f08a2ccd61e3ef52115e6e7c571582de@chromium.org>

ppy/angle,ppy/angle,ppy/angle,ppy/angle