Add rumba build and bring up rumbad in stdout mode

Description

This PR extends the e2e test to build the rumba repository, which will allow us to catch any breaking changes made in buildbox-common or recc. It also brings up a rumbad server in stdout mode, which writes to a file to allow tests to inspect output if necessary.

This PR adds no such tests yet, but as is this change will test the rumba and rumbad builds, along with testing that rumbad starts up successfully.