Reorganize some code and add the start of the transport file parsing

src/properties/utils.rs

@@ -0,0 +1,14 @@
+pub fn parse_fields(line: &str, widths: &[usize]) -> Vec<String> {
+    let mut fields = Vec::new();
+    let mut pos = 0;
+
+    for &width in widths {
+        if let Some(field) = line.get(pos..pos + width) {
+            // The replace changes the fortran formatted D exponential for the normal E exponential
+            fields.push(field.trim().replace("D", "E").replace("E ", "E"));
+        }
+        pos += width;
+    }
+
+    fields
+}