Add command_with_transition macro.

[oxidase]

@keith I have prepared another PR that breaks the current behavior which forces commands to make a transition to the "opt" compilation mode. Such implicit transition requires rebuilds of dependencies if a non-"opt" mode is used for building and testing before running multirun targets. In my example building of an image is done in the default fastbuild mode:

bazel build --platforms //deploy:aws_batch //src:image -s
...
  bazel-out/darwin_arm64-fastbuild-ST-445ab20d0084/bin/src/layer.build)
# Configuration: 0bee61ed503b09c25677365e3af314e0bdc31e8c9a0fdadd7381edaeff2222ab
...

but deploying the pre-built image with a multirun rule deploy forces another rebuild in opt mode`

bazel build //deploy:aws_batch //src:deploy -s
...
  bazel-out/darwin_arm64-opt-ST-445ab20d0084/bin/src/layer.build)
# Configuration: 318688f3701ef1fef848ac612bbc338ed2687e6287631dbcfc5499a3febae5d0

which involves Docker create commands and takes some minutes.

The PR is similar to #17:

• adds command_with_transition macro
• aligns multirun and command configurations to "target"
• adds command_force_opt which keeps previous behavior of command
• updates some tests