UPDATE: Adds name validation and exposes it in wasm

We do a trick I am not proud of. Because all of our errors are Strings,
we don't have a way to separate a name error from an index error,
for instance. What I do in prepend the error with a string that indicates
where it comes from.

base/src/user_model/common.rs

@@ -2001,7 +2001,10 @@ impl UserModel {
         new_scope: Option<u32>,
         new_formula: &str,
     ) -> Result<(), String> {
-        let old_formula = self.model.get_defined_name_formula(name, scope)?;
+        let old_formula = self
+            .model
+            .get_defined_name_formula(name, scope)
+            .map_err(|_| "General: Failed to get old name")?;
         let diff_list = vec![Diff::UpdateDefinedName {
             name: name.to_string(),
             scope,
@@ -2017,6 +2020,16 @@ impl UserModel {
         Ok(())
     }
 
+    /// validates a new defined name
+    pub fn is_valid_defined_name(
+        &self,
+        name: &str,
+        scope: Option<u32>,
+        formula: &str,
+    ) -> Result<Option<u32>, String> {
+        self.model.is_valid_defined_name(name, scope, formula)
+    }
+
     // **** Private methods ****** //
 
     pub(crate) fn push_diff_list(&mut self, diff_list: DiffList) {