Address sonar issues in drools-pdp

Address sonar issues in drools-pdp

Addressed the following sonar issues:
- add "final" to public static fields
- commented code; some were bogus - just updated the comments
  so sonar is happy
- use "{}" instead of string concatenation
- junit should assert something
- when using logger, invoke compute-intensive tasks conditionally
- use superclass name instead of subclass name to access static fields
- don't always return the same value
- remove "transient" from fields of classes that aren't Serializable
- don't nest try/catch blocks
- use appropriate class name in Logger.getLogger()
- use Predicate<T> instead of Function<T,Boolean>
- remove unused parameters from private methods
- either log or throw
- remove duplicate methods
- use remove() TLS instead of set(null)
- null check is implicit in instanceof check
- do something with return value
- don't use volatile
- don't return "null" list; used Optional instead
- add no-arg constructor to non-Serializable superclass
- add callSuper=true for EqualsAndHashCode
- don't declare "throws XXX" where XXX is a subclass of RuntimeException
- remove serialVersionUID field if the class isn't Serializable

Also addressed some eclipse warnings:
- unused fields
- suppress generic typic cast warnings

Issue-ID: POLICY-2305
Change-Id: I906d5bf71c1f86531423e23b3667a585cdba45e1
Signed-off-by: Jim Hahn <jrh3@att.com>