Fix #9363: Code hints popup dismisses prematurely

I moved the logic to restore the collapsed files to the template, so that we don't need to toggle them after the results UI is rendered.
It doesn't seem necessary to have mutually exclusive `expanded` and `collapsed` classes since you can check for the presence versus absence of a single class.

I can only find a single place the `collapsed` class is used in **brackets.less**:

```css
.search-results .disclosure-triangle,
#problems-panel .disclosure-triangle {
    .jstree-sprite;
    display: inline-block;
    &.expanded {
        // Unfortunately, the way jsTree sprites are aligned within their 18px boxes doesn't look good in
        // other contexts, so we need some tweaks here instead of straight multiples of @jstree-sprite-size
        background-position: 7px 5px;
        -webkit-transform: translateZ(0) rotate(90deg);
    }
    &.collapsed {
        background-position: 7px 5px;
    }
}
```

`background-position` is the same for both cases, so this should be simplified to removes the reference to the `collapsed`:

```css
.search-results .disclosure-triangle,
#problems-panel .disclosure-triangle {
    .jstree-sprite;
    display: inline-block;
    background-position: 7px 5px;
    &.expanded {
        // Unfortunately, the way jsTree sprites are aligned within their 18px boxes doesn't look good in
        // other contexts, so we need some tweaks here instead of straight multiples of @jstree-sprite-size
        -webkit-transform: translateZ(0) rotate(90deg);
    }
}
```