Moved matcher-based capture macros into their own file

- this file excluded from the CATCH_CONFIG_DISABLE_MATCHERS path.
- matchers are always compiled in to the impl file
- _THROWS_WITH macros are still available with matchers disabled - but only the ones that take a string
- tests that use matchers have #ifdefs, so the whole SelfTest project can compile with matchers disable.

projects/SelfTest/CompilationTests.cpp

@@ -43,7 +43,9 @@ bool templated_tests(T t) {
     REQUIRE_THROWS(throws_int(true));
     CHECK_THROWS_AS(throws_int(true), int);
     REQUIRE_NOTHROW(throws_int(false));
+#ifndef CATCH_CONFIG_DISABLE_MATCHERS
     REQUIRE_THAT("aaa", Catch::EndsWith("aaa"));
+#endif
     return true;
 }