Spring-ai Make filter expression builder op public

Following the simple example for filter expressions, when I do the following:

val b = FilterExpressionBuilder()
val expression: Expression = b.eq("state", "Oregon").build()

I get these errors:

Type FilterExpressionBuilder.Op! is inaccessible in this context due to: public/*package*/ final class Op
Cannot access 'Op': it is package-private in 'FilterExpressionBuilder'

I think the fix is simply making it public.

Comment From: tzolov

Rebased, squashed and merged at: 837c4080aa06f04b9f3c007ebfba6fc67be1b1ca