FilterState.filters stream not updated on FilterState.clear

**Describe the bug 🐛**

I have a `FilterState` and listen to the `filterState.filters` stream for updates. When adding filters i receive updates, but not when calling `filterState.clear`.

**To Reproduce 🔍**

1. create a `FilterState` instance
2. listen to the `FilterState.filters` stream using a `StreamBuilder`
3. add filters and confirm we receive stream updates
4. add a button which calls `filterState.clear` and confirm the `StreamBuilder` does not receive an update

**Expected behavior 💭**

I'd expect `StreamBuilder` to receive an update when calling `filterState.clear`

**Screenshots 🖥**

**Environment:**

- OS: iOS
- Library Version ^0.2.3

**Additional context**

flutter --version

```
Flutter 3.7.6 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 12cb4eb7a0 (8 days ago) • 2023-03-01 10:29:26 -0800
Engine • revision ada363ee93
Tools • Dart 2.19.3 • DevTools 2.20.1
```

Start by locating FilterState.clear and the FilterState.filters stream, then trace how adding filters emits updates. Confirm completion when calling clear causes StreamBuilder listeners to receive an update; the report provides no file or test path, so inspect the relevant implementation and tests.

Written by the indexing model from the issue text.