Fix STORE-405

This commit addresses  STORE-405: Search Fields should be rendered based on RXT Definition.

The cause of the problem was based on the fact that we were not reading the label attributes from the name element.In order to fix this, the label was parsed and added to the field.

If this fix needs to be applied in isoation the following files must be updated;

**Theme files**:
/store/default/partials/search.hbs
/store/default/js/search.js
/store/default/partials/search-field.hbs

**Module files**:
/store/modules/rxt/scripts/form.overview.exporter.js
/store/modules/rxt/converter.js
/store/modules/ext/core/extension.parser.js

This fix also renders any options fields as select boxes in the search form.