Initial commit for api.js

- GET JSON call with console output
- Provide filters

InvenTree/static/script/inventree/api.js

@@ -0,0 +1,21 @@
+function inventreeGet(url, filters={}) {
+    $.ajax({
+        url: url,
+        type: 'get',
+        data: filters,
+        dataType: 'json',
+        success: function(response) {
+            console.log('Success GET data at ' + url);
+            return response;
+        },
+        error: function(xhr, ajaxOptions, thrownError) {
+            console.error('Error on GET at ' + url);
+            console.error(thrownError);
+            return {};
+        }
+    })
+}
+
+function getParts(filters={}) {
+    return inventreeGet('/api/part/', filters);
+}