GH-45564: [C++][Acero] Add size validation for names and expressions vectors in ProjectNode (#45565)

### What changes are included in this PR?
Added a check to validate that the sizes of the names and expressions vectors match in the ProjectNode class

### Are these changes tested?
Yes

### Are there any user-facing changes?
No

* GitHub Issue: #45564

Lead-authored-by: kamilt <[email protected]>
Co-authored-by: mroz45 <[email protected]>
Co-authored-by: Rossi Sun <[email protected]>
Signed-off-by: Rossi Sun <[email protected]>

Author: mroz45

cpp/src/arrow/acero/plan_test.cc

@@ -1266,6 +1266,23 @@ TEST(ExecPlanExecution, SourceFilterProjectGroupedSumFilter) {
   }
 }
 
+TEST(ExecPlanExecution, ProjectNamesSizeMismatch) {
+  auto input = MakeGroupableBatches();
+
+  Declaration plan = Declaration::Sequence(
+      {{"source", SourceNodeOptions{input.schema, input.gen(true, /*slow=*/false)}},
+       {"project", ProjectNodeOptions{
+                       /*expressions=*/{field_ref("str"),
+                                        call("multiply", {field_ref("i32"), literal(2)})},
+                       /*names=*/{"a"}}}});  // expected 2 names but only 1 provided
+
+  EXPECT_RAISES_WITH_MESSAGE_THAT(
+      Invalid,
+      ::testing::HasSubstr(
+          "Project node's size of names 1 doesn't match size of expressions 2"),
+      DeclarationToTable(std::move(plan)));
+}
+
 TEST(ExecPlanExecution, SourceFilterProjectGroupedSumOrderBy) {
   for (bool parallel : {false, true}) {
     SCOPED_TRACE(parallel ? "parallel/merged" : "serial");

cpp/src/arrow/acero/project_node.cc

@@ -59,8 +59,13 @@ class ProjectNode : public MapNode {
       for (size_t i = 0; i < exprs.size(); ++i) {
         names[i] = exprs[i].ToString();
       }
+    } else {
+      ARROW_RETURN_IF(
+          names.size() != exprs.size(),
+          Status::Invalid("Project node's size of names " + std::to_string(names.size()) +
+                          " doesn't match size of expressions " +
+                          std::to_string(exprs.size())));
     }
-
     FieldVector fields(exprs.size());
     int i = 0;
     for (auto& expr : exprs) {