(pup-546) Remove hiera2 support from binder

This removes hiera2 support from binder.
Tests are updated to use ruby based bindings for the same data bindings
as the removed hiera2 based bindings.
(pup-546) Remove automatic injector lookup for class parameters.
(pup-546) Remove hiera2.rb (central file with require's for hiera2)
(pup-546) Update default.rb and remove mention of hiera2

The documentation for the --binder setting is updated to reflect
that hiera2-data-in-modules is no longer loaded, while still allowing
bindings to be made in ruby, now referred to as "bindings in modules".
(PUP-546) Replace lookup function with something useful

With removed hiera2, the lookup function is not as useful and is
now replaced with the lookup from (#22574) which first looks in
bound data and then in hiera.

The intent is to use the technolgy agnostic "lookup" in the future
parser/evaluator to enable shorthand notation. The actual lookup
mechanism/technology is thereby not visible to the user.
(PUP-546) Fix problems with lookup after removal of hiera2

Moved lookup functionality to separate helper class.
Merge pull request #2188 from hlindberg/pup-546_remove-hiera2-data-in-modules

(PUP-546) remove hiera2 part of data in modules