Replace missmatch_object with invalid_object

Replace missmatch_object with invalid_object

Modifies the missmatch_object (sic) test for glCopyImageSubData into an
invalid object test. The changes clarify what the test is actually
testing, and avoids an issue where an unexpectedly valid object name
could cause the test to fail.

Also fixes the spelling of 'mismatch' in several places, corrects the
description for Test [C], and corrects mention of 'CopyImageSubData'.

Components: OpenGL

VK-GL-CTS issue: 669

Affects:
* KHR-GL43/44/45/46.copy_image.missmatch_object, which are now
* KHR-GL43/44/45/46.copy_image.invalid_object
* KHR-GL43/44/45/46.copy_image.samples_missmatch, which are now
* KHR-GL43/44/45/46.copy_image.samples_mismatch

Change-Id: I5127435afc1c116df3d4fa8d6d78397069255603