* Fix compilation with -Wsign-conversion
For tests with GCC and Clang
Fixes https://github.com/ETLCPP/etl/issues/632
* Fix support of negative Id in type_lookup.h: type_from_id
* Fix element access arithmetic in atomic_gcc_sync.h fetch_add/fetch_sub
* Fix rounded_integral_division.h: divide_round_half_odd(): direction is always 1
C++14 compiler compatibility
Updated test run scripts
Changed some ETL_ASSERT macros to ETL_ASSERT_OR_RETURN
Changed unit test macros for C++20 compaibility
Updated test run scripts
Updated CMake files to allow C++ standard selection
Replaced ETL_ASSERT_AND_RETURN with ETL_ASSERT_OR_RETURN
Updated C++14 & C++20 unit test compatibility
Changed native char8_t check
Added optional optimisation argument to bash script
* Provide cmake library for UnitTest++.
Prefer cmake target_* commands.
* Replace wrong cmake link options with compile
* We need the sanitize flags also in linker