Add missing AST query methods to Java API (#8977)

* add Expr.isGround() to Java API

Expose Z3_is_ground as a public method on Expr. Returns true when the
expression contains no free variables.

* add Expr.isLambda() to Java API

Expose Z3_is_lambda as a public method on Expr. Returns true when the
expression is a lambda quantifier.

* add AST.getDepth() to Java API

Expose Z3_get_depth as a public method on AST. Returns the maximum
number of nodes on any path from root to leaf.

* add ArraySort.getArity() to Java API

Expose Z3_get_array_arity as a public method on ArraySort. Returns
the number of dimensions of a multi-dimensional array sort.

* add DatatypeSort.isRecursive() to Java API

Expose Z3_is_recursive_datatype_sort as a public method on
DatatypeSort. Returns true when the datatype refers to itself.

* add FPExpr.isNumeral() to Java API

Expose Z3_fpa_is_numeral as a public method on FPExpr. Returns true
when the expression is a concrete floating-point value.

* add isGroundExample test to JavaExample

Test Expr.isGround() on constants, variables, and compound
expressions.

* add astDepthExample test to JavaExample

Test AST.getDepth() on leaf nodes and nested expressions to verify
the depth computation.

* add arrayArityExample test to JavaExample

Test ArraySort.getArity() on single-domain and multi-domain array
sorts.

* add recursiveDatatypeExample test to JavaExample

Test DatatypeSort.isRecursive() on a recursive list datatype and a
non-recursive pair datatype.

* add fpNumeralExample test to JavaExample

Test FPExpr.isNumeral() on a floating point constant and a symbolic
variable.

* add isLambdaExample test to JavaExample

Test Expr.isLambda() on a lambda expression and a plain variable.

src/api/java/AST.java

@@ -80,6 +80,16 @@ public class AST extends Z3Object implements Comparable<AST>
         return Native.getAstId(getContext().nCtx(), getNativeObject());
     }
 
+    /**
+     * The depth of the AST (max nodes on any root-to-leaf path).
+     * @throws Z3Exception on error
+     * @return an int
+     **/
+    public int getDepth()
+    {
+        return Native.getDepth(getContext().nCtx(), getNativeObject());
+    }
+
     /**
      * Translates (copies) the AST to the Context {@code ctx}. 
      * @param ctx A context