OOPathExpr generation (#1528)
* Implementation of OOPathExpr
Added simpler test case for OOPath
* Removed processing of RuleImpl
* Refactor
* Refactor FromVisitor to use optional initializer expression in the DeclarationSpec
* Moved extractGenericType to ClassUtils.java
Renamed to DeclarationSource
use Option.ifPresent rather thatn optToStream.forEach
Removed unused RuleImpl
* Use monadic flatMap rather than using two different constructors