This patch implements all the program queries on the geometry
shader stage of a program by glGetProgramiv(), including the
queries on geometry shader input/output primitives, invocations
and maximum output vertices

BUG=angleproject:1941
TEST=dEQP-GLES31.functional.geometry_shading.query.geometry_linked_*
     dEQP-GLES31.functional.geometry_shading.query.geometry_shader_invocations
     dEQP-GLES31.functional.state_query.program.geometry_shader_state_get_programiv

Change-Id: Ibfa630c64dba5baf52ff84ce7e0bf4c567eef8c4
Reviewed-on: https://chromium-review.googlesource.com/961397
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jiajia Qin <jiajia.qin@intel.com>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>