FilterInterpreter doesn't use selector for filtering.

## Type of Issue

Select the type of issue:
- [ ] Bug report (to report a bug)
- [ ] Feature request (to request an additional feature)
- [ ] Tracker (I am just using this as a tracker)
- [x] Refactor request
- [ ] Documentation Ask

## Description

Right now we have (maybe_apply_selector)[https://github.com/facebookresearch/fairo/blob/main/droidlet/interpreter/interpret_filters.py#L341] being applied in FilterInterpreter but `interpret_reference_object` already strips out this field [here](https://github.com/facebookresearch/fairo/blob/main/droidlet/interpreter/interpret_reference_objects.py#L190) before calling this method. I propose we remove it in one of the places to improve code understandability.