App: Create addTranslatableExportType method

This method aims to solve the problem of untranslatable description
strings on file types. Some, but not all, file format description
strings contain translatable elements. For example, some languages
may translate "FEM mesh formats". Many format descriptions include
the words "file," "format," or "mesh" -- these could potentially be
replaced with localized versions.

src/App/ApplicationPy.cpp

@@ -89,6 +89,12 @@ PyMethodDef ApplicationPy::Methods[] = {
      (PyCFunction)ApplicationPy::sAddExportType,
      METH_VARARGS,
      "Register filetype for export"},
+    {"addTranslatableExportType",
+     (PyCFunction)ApplicationPy::sAddTranslatableExportType,
+     METH_VARARGS,
+     "addTranslatableExportType(description:str, extensions:list[str], module_name:str)\n\n"
+     "Register filetype with translatable description for export. Description should be a\n"
+     "string registered with the translation system using the 'FileFormat' context."},
     {"changeExportModule",
      (PyCFunction)ApplicationPy::sChangeExportModule,
      METH_VARARGS,
@@ -751,6 +757,47 @@ PyObject* ApplicationPy::sAddExportType(PyObject* /*self*/, PyObject* args)
     Py_Return;
 }
 
+PyObject* ApplicationPy::sAddTranslatableExportType(PyObject* /*self*/, PyObject* args)
+{
+    char *description {};
+    PyObject *pyExtensions {};
+    char *moduleName {};
+
+    if (!PyArg_ParseTuple(args, "sOs", &description, &pyExtensions, &moduleName)) {
+        return nullptr;
+    }
+
+    if (!PyList_Check(pyExtensions)) {
+        PyErr_SetString(PyExc_TypeError,
+                        "Expected a list of strings as second argument");
+        return nullptr;
+    }
+
+    Py_ssize_t n = PyList_Size(pyExtensions);
+
+    std::vector<std::string> extensions;
+    for (Py_ssize_t i = 0; i < n; ++i) {
+        PyObject *item = PyList_GetItem(pyExtensions, i);
+
+        if (!PyUnicode_Check(item)) {
+            PyErr_SetString(PyExc_TypeError,
+                            "Extensions list elements must be strings");
+            return nullptr;
+        }
+
+        const char *value = PyUnicode_AsUTF8(item);
+        if (!value) {
+            return nullptr;
+        }
+
+        extensions.emplace_back(value);
+    }
+
+    GetApplication().addTranslatableExportType(description, extensions, moduleName);
+
+    Py_Return;
+}
+
 PyObject* ApplicationPy::sChangeExportModule(PyObject* /*self*/, PyObject* args)
 {
     char *key {};