Setup Rust QNX target build in Dockerfile

[MarkSchmitt]

Write a Dockerfile that downloads and builds a Rust nto-qnx target (SDP 7.1.0 because 8.0.0 doesn't fully function yet) with the use of a pre-installed SDP.

The user still needs a valid QNX SDP and License, but we should be able to provide a Dockerfile that makes it straightforward to build a devcontainer that can compile for QNX targets.

Also add dependencies for bazel, so we can use the bazel qnx_toolchain as well, then things should fall into place and devs should be able to get started quickly

ACs:

• Create a repository with a Dockerfile and possibly helper scripts to build the nto-qnx rust target
• Provide easy means to use the rustc target with cargo
• Provide examples with a simple project that compiles and can be run
• Provide examples how to create a QNX VM, just a quick startup guide
• Optional: integrate support for bazel / the qnx_toolchain so there are no road blocks (i.e. missing libraries, tools, bazel dependencies ) for using it

[MarkSchmitt]

PR for Dockerfiles and howto is up here: eclipse-score/toolchains_rust#1