Add draft for binary switch based on extended CAPSSession

[s1ck]

Extends CAPSSession with SPIP API via mixin trait. The trait and necessary adapters are bundled within a single package. This allows a seamless switch between SPIP and OKAPI API in a single graph app by switching the session implementation. See GraphApp for an example.

Pro:

• no additional module
• seamless binary switch between CAPS and SPIP
• CAPS spark-cypher can be renamed to morpheus-spark-cypher or morpheus

Cons:

• as with v1, it feels a bit weird that similar named methods return equally named results but with different semantics, but I guess that's what we just need to deal with

Needs apache/spark#24297 installed locally to compile and run.

[Mats-SX]

I think I like this one better than the alternative, but I'm not sure I understand all of the implications. Very nice examples though!