Create a bridging module so that 'Emmy' equations can be passed to Wolfram and vice-versa

[holyjak]

Emmy is "computer algebra system written in Clojure(Script)" and works on symbolic expressions, which it can simplify and eventually evaluate. However, it is still limited in which expressions it can evaluate. Wolfram has a richer set of capabilities. The idea is to make it possible to plug Wolfram(ite) into Emmy as an evaluation backend for [some] expressions.

This would require translating between Emmy's and Wolfram's expressions, e.g. ** <-> Power.

Proposed by @light-matters