When handling tessellation shaders these 2 requirements need to be met -
1. TCS - vertex count should be declared at least once
2. TES - primitive mode should be declared at least once

After translating TCS/TES check whether these requirements are met
and error out if they are not.

Bug: angleproject:5557
Test: dEQP-GLES31 -
        functional.shaders.linkage.es31.tessellation.varying.rules.unspecified_*
      KHR-GLES32 -
        core.tessellation_shader.compilation_and_linking_errors.te_lacking_primitive_mode_declaration
Change-Id: I727d548ad446646bbece1fb78197639537b5f395
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2714465Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Mohan Maiya <m.maiya@samsung.com>