Better Rails engine support #3647
Description
We currently don't add the Rails add-on if the workspace structure doesn't include a bin/rails. This means that we sometimes miss Rails engines that don't define this file, which isn't great as they then lose support for running tests through the explorer among other things.
Maybe we can include the add-on on more conditions and do the work to ensure that it won't crash when running in an engine without bin/rails, so that support is improved.