Add support for building C++ with Gradle

[spacey-sooty]

Is your feature request related to a problem? Please describe.
I am trying to utilise rerun for on robot logging in FRC. Our build system is heavily embedded in Gradle. Normally if we want to include a library we use a git submodule and include it into our project through that. This requires that we can build the project in Gradle.

Describe the solution you'd like
Support for building the C++ project in Gradle.

Describe alternatives you've considered
Static binary releases with a header file could also work.

Additional context
Our build system uses GradleRIO which is built on Native Utils

[Wumpf]

If you figure out a good Gradle integration, we'd be happy to link to an example for this, but at the moment we don't want to add "official" support to additional build systems for C++ due to the myriad of options and high maintenance burden.

As for providing binaries, we haven't entirely made up our mind yet: We have std types in our C++ interface meaning that we strictly speaking need a binary for every version of os/compiler/std-lib combination since there is generally no binary compatibility.

That said, the upcoming 0.11 release / the main branch adds a lot of documentation around how to build the C++ SDK from scratch, as well as CMake Install support to build your own binaries in a controlled fashion.

[spacey-sooty]

Sounds good to me! Thanks for the help!