Vertexwahn

I created an experiment [here](https://github.com/Vertexwahn/rules_qt6) using Qt6. The idea here is to use a prebuild version of Qt and use dynamic linking.

+1

This is what the .`bazelci/presubmit.yml` looks like: ``` --- tasks: ubuntu2004: platform: ubuntu2004 shell_commands: - "sudo apt update && sudo apt -y install qt5-default qtdeclarative5-dev" build_targets: - "//..." macos: shell_commands:...

a private brew would be nice

@horenmar Can you please review?

@horenmar Currently the Bazel build of Catch2 is broken. This PR is going to fix this (proper handing of `CATCH_CONFIG_SHARED_LIBRARY`)

Adding `copts = ["-std=c++14"]` does not make sense. Since GCC and Visual Studio handle it in a different way, we have configs for this. See [`.bazelrc`](https://github.com/catchorg/Catch2/blob/devel/.bazelrc). `bazel build --config=gcc9 //...`...

Same problem with CLion 2022.1.3 Bazel Plugin: 2022.07.25.0.1-api-version-221 Bazel: 5.2.0

@jheaff1 Just read it now - sorry - feel free to provide a PR to https://github.com/Vertexwahn/rules_qt6

[Vertexwahn/rules_qt6](https://github.com/Vertexwahn/rules_qt6) fetches on Windows and Linux a prebuild version of Qt6 - no need to preinstall anything - on macOS it is still required to preinstall Qt6 (`brew install qt6`)...