join constraints are ignored when BigDecimal equality is involved in a Pattern

Issue Description:
For example,

    when
        $p1 : Person( name == "John" )
        $p2 : Person( name == "Paul", age == $p1.age, salary == $p1.salary )

John : age = 30, salary = 10
Paul : age = 28, salary = 10

This rule should not match because ages are not the same. However, it matches. This issue is caused by DROOLS-7085 which employs TupleList instead of TupleIndexHashTable while other hashable beta constraints are marked is "indexed".

Acceptance Criteria:

• Use TupleIndexHashTable if there are other hashable beta constraints.
• Exclude BigDecimal equality constraint from index and mark it indexed=false so that it will be asserted on PhreakJoinNode.