Make Lando verbosity available to build steps and tooling

[AaronFeledy]

I have a project with some fairly complicated build steps and tooling. I manage these with several complicated scripts that are capable of producing debug output. With Lando tooling, when you add -vvv you get Lando's debug output, but my scripts are also able to grab that -vvv and produce debug output. However, if I lando start -vvv or lando rebuild -vvv the verbosity flag doesn't get passed into scripts executed in build steps.

Lando should generate an environment variable to represent the verbosity level that was passed to Lando when running either tooling or build commands. This will allow scripts to consistently determine the level of output that is expected.