Handle high-volume terraform outputs better than Atlantis

[ZIJ]

Full commit logs is nice, but having consolidated view be good - to see relevant information

[ZIJ]

tagging @jdziat

[ZIJ]

The other idea suggested by @jdziat for "dry run / readonly mode" tracked in #237

[frank-bee]

To start with, you could just use the same output like Atlantis. This makes it also easier for users to switch from Atlantis to digger.

E.g.