Auto-track all bridge files

[nyurik]

Adds cargo:rerun-if-changed=<path> for all files used by the bridge.

Note that when I went through all the rerun-if-changed cases, some of them did not include the .rs file - which may mean that even this repo is missing the needed tracking and this would fix those.

Fixes #1461

[dtolnay]

See previous consideration of this in #26. I think it's better not to do this.

[nyurik]

@dtolnay thx, i didn't see that PR. Do you think cxx could adapt the approach to other similar crates like static_files change_detection? It has a builder that allows to enable change detction print statements, and afterwards it finalizes it.

The issue with cxx is that it produces a cc::Build directly - making it somewhat inconvinient when additional configurations are needed. Perhaps we can introduce a new Bridge or CxxBuild struct?

    cxx_build::new()  // empty CxxBuild
        .add_bridge("src/map_renderer.rs") // add a single bridge file
        .change_detection() // enable "rerun-if-changed" printing
        .to_bridge()  // consume CxxBuild and create cc::Build -- prints rerun-if-changed here
        .includes(&include_dirs)  // Just as before - operations on the cc::Build
        .file("src/renderer/bridge.cpp")
        .flag_if_supported("-std=c++20")
        .compile("maplibre_rust_map_renderer_bindings");

[dtolnay]

I don't think a separate builder type is justified. But it could be done using CFG.

[nyurik]

Thx, I created #1463 to do that