Move metadata extension with property order from kotlinx.serialization to core
After fix of KT-54792 properties will be deserialized in declaration order
if corresponding class was compiled with modern compiler. But this order
is needed for kotlinx.serialization for binaries compiled with any
kotlin compiler >= 1.4. Since we don't plan to add any extension points
into (de)serialization into FIR, we need to take into account existing
metadata extension from kotlinx.serialization in compiler itself
^KT-57769 Fixed
Disable it if we do not have required `noCompiledSerializer` function in
runtime. Leave it enabled in tests.
Rollback some changes for old backend as it is unsupported now.
Dmitriy Novozhilov