to make sure that error tests do not fail because they become outdated

since it takes too much time to complete, similar to other tests with additional
CMake invocation

It disables entire branch of tests declaration unconditionally because CXX_STANDARD
is not defined there. But even we use CMAKE_CXX_STANDARD here, these tests should
not be disabled with standard >= C++20.

* Don't explicitly delete copy ctor of dynamic_format_arg_store

Explicitly deleting the copy ctor causes the move constructor to not be
implicitly generated. This behaviour is different than what was in
v8.0.1 and causes code that relied on the move ctor of
dynamic_format_arg_store to break.

* Add test for dynamic_format_arg_store's move ctor

* include <memory>, don't use make_unique

Signed-off-by: Stefan Weil <sw@weilnetz.de>

works only if all named arguments are UDL-based