Emit a detailed deprecation warning that explains what to do instead.
Also add a unittest.
```
DEPRECATION: target prog links against shared module mymod, which is incorrect.
This will be an error in the future, so please use shared_library() for mymod instead.
If shared_module() was used for mymod because it has references to undefined symbols,
use shared_libary() with `override_options: ['b_lundef=false']` instead.
```
Fixes https://github.com/mesonbuild/meson/issues/9492
Nirbheek Chauhan