Improve compil time of cargo-prosa package

[reneca]

The compilation take a lot of time due to build.rs script from a cargo-prosa package.

This is visible through cargo build --timings

The time, come from a sub package generated by the build.rs script to generate configuration files.
It need to be done in another way to gain time.

One thing that could be done, is to do a macro to generate the configuration file.

[reneca]

To improve this, I tried to create a link of the target/ folder to not recompile everything.
Unfortunately, it's not working. There is a lock.

But maybe we can use Rust Build Cache.
It'll specify the target-dir to be the same as the ProSA instance.

First we need to solve the #56