Compile mbedtls code directly

With this method, we are only importing the mbedcrypto library files and are
compiling them using meson/ninja direclty inside our main project.
This seems to solve all the cross-compiling issues and has no downside.
For the systems that already have the library installed, the compile
script will use that one instead by default.
5 jobs for mbedtls_internal_code in 1 minute and 7 seconds (queued for 1 second)