[Docker] Install some system utilities in base image

Despite the desire to keep the base image slim, we should consider adding some helpful tools:

• curl
• less
• pspg (also configure environment for dbshell)

@debdolph Anything else you are missing?

assigned to @nik

changed the description

created merge request !870 (merged) to address this issue

mentioned in merge request !870 (merged)

closed with merge request !870 (merged)

mentioned in commit e8d04b41