topic-title-list is use in category and talk overlay.
Rather than relying on jQuery selectors to update these, it might be better to think of this as a component that's included inside the TalkOverlay and CategoryOverlay.
This task encompasses the work to:
[ ] Create a TopicTitleList unordered list component. The component should supply a trim API that supports existing use cases including `clear()` and `add()`.
[ ] Replace inline `<ul class=topic-title-list>` usages with new TopicTitleList component.
```
docfix x ~/git/core/extensions/MobileFrontend $ ag "topic-title-list" resources/
resources/mobile.categories.overlays/CategoryOverlay.hogan
12: <ul class="topic-title-list normal-catlist"></ul>
13: <ul class="topic-title-list hidden hidden-catlist"></ul>
resources/mobile.categories.overlays/CategoryOverlay.js
148: this.$( '.topic-title-list' ).toggleClass( 'hidden' );
resources/mobile.pagelist.styles/pagelist.less
36:.topic-title-list,
150: .topic-title-list,
resources/mobile.talk.overlays/content.hogan
5: <ul class="topic-title-list">
resources/mobile.talk.overlays/TalkOverlay.js
97: this.$( '.topic-title-list' ).empty();
```