add type resolving for structs and fn params

- add a printer for the symbol table
 - add error contexts to type pass

examples/hello.ry

@@ -1,5 +1,18 @@
 // import std;
 
+struct B {
+    field i32
+}
+
+struct Awoo {
+    b B
+    other_field i32
+}
+
+fn test_function() Awoo {
+    return 1;
+}
+
 fn multwo(num: i32, double_flag: bool) i32 {
     // TODO resolve expr variables
     if (true) {