fix struct/interface/logic conversion interactions

- interface conversion only waits for type resolution of modports
- typeof conversion resolves struct field accesses
- logic conversion only converts logic data declarations
- struct conversion only converts within modules
- fix nested type traversal order causing premature struct conversion

test/basic/interface_struct.sv

@@ -0,0 +1,30 @@
+typedef struct packed {
+    logic c, d;
+} T;
+typedef struct packed {
+    logic a, b;
+    T y;
+} S;
+
+interface I;
+    S x;
+    type(x.y) w;
+    modport D(input x);
+endinterface
+
+module M(m);
+    I.D m;
+    initial begin
+        $display("%b", m.x.a);
+        $display("%b", m.x.b);
+        $display("%b", m.x.y.c);
+        $display("%b", m.x.y.d);
+    end
+endmodule
+
+module top;
+    I i();
+    M m(i);
+    assign i.x = 4'b1001;
+    initial i.w = 2'b10;
+endmodule