Tests: Don't expect the Tests dir to be called 'Tests'.

A follow-up commit will make it change depending on
the CMAKE_TEST_GENERATOR.
Tests: Use CMAKE_CURRENT_BINARY_DIR instead of Tests/ reference.
Tests: Disable CMake binary tests for different test generator.
Tests: Use CMAKE_TEST_GENERATOR where intended.
Tests: Use CMAKE_CURRENT_BINARY_DIR in configure_file context.

Trivially modify the input files which are configured from the
Tests/ directory.
Tests: Build alt-test-generator tests in a separate binary dir.

This way, a single CMake build tree can be used to run the
unit tests with multiple generators.
Merge topic 'alt-test-generator' into next

eb6e4b7d Tests: Build alt-test-generator tests in a separate binary dir.
1333a583 Tests: Use CMAKE_CURRENT_BINARY_DIR in configure_file context.
f6d69b4b Tests: Use CMAKE_TEST_GENERATOR where intended.
bc60d4b3 Tests: Disable CMake binary tests for different test generator.
53858649 Tests: Use CMAKE_CURRENT_BINARY_DIR instead of Tests/ reference.
cfb566a6 Tests: Don't expect the Tests dir to be called 'Tests'.