checker: add a return *x suggestion, to the error fn ... expects you to return a non reference type ..., but you are returning ... instead

vlib/v/checker/return.v

@@ -184,6 +184,7 @@ fn (mut c Checker) return_stmt(mut node ast.Return) {
 			if node.exprs[expr_idxs[i]].is_auto_deref_var() {
 				continue
 			}
+			c.add_error_detail('use `return *pointer` instead of `return pointer`, and just `return value` instead of `return &value`')
 			c.error('fn `${c.table.cur_fn.name}` expects you to return a non reference type `${c.table.type_to_str(exp_type)}`, but you are returning `${c.table.type_to_str(got_typ)}` instead',
 				pos)
 		}

vlib/v/checker/tests/return_ref_as_no_ref_bug.out

@@ -5,3 +5,4 @@ vlib/v/checker/tests/return_ref_as_no_ref_bug.vv:11:9: error: fn `return_not_ref
       |            ^
    12 |         id: 1
    13 |     }
+Details: use `return *pointer` instead of `return pointer`, and just `return value` instead of `return &value`

vlib/v/checker/tests/union_unsafe_fields.out

@@ -17,3 +17,4 @@ vlib/v/checker/tests/union_unsafe_fields.vv:11:9: error: fn `f` expects you to r
    11 |     return &u.f
       |            ^
    12 | }
+Details: use `return *pointer` instead of `return pointer`, and just `return value` instead of `return &value`