Add GlobalPool test

Author: aurorarossi

GNNLux/test/layers/pool.jl

@@ -0,0 +1,15 @@
+@testitem "Pooling" setup=[TestModuleLux] begin
+    using .TestModuleLux
+    @testset "GlobalPool" begin
+
+        rng = StableRNG(1234)
+        g = rand_graph(rng, 10, 40)
+        in_dims = 3
+        x = randn(rng, Float32, in_dims, 10)
+
+        @testset "GCNConv" begin
+            l = GlobalPool(mean)
+            test_lux_layer(rng, l, g, x, sizey=(in_dims,1))
+        end
+    end
+end