compile modules via nginx's configure tool

[ivanitskiy]

Is your feature request related to a problem? Please describe.
It would be beneficial to allow building/compiling dynamic modules using a standard way that is used to build C-based modules like
./configure --add-dynamic-module=/opt/source/ngx_rust_my_module/

Further reading:

• https://www.nginx.com/resources/wiki/extending/new_config/
• https://www.nginx.com/resources/wiki/extending/converting/

By doing so ngx-rust-based modules would be easer to build at the same time when nginx is building itself.