Similar to interpolation, we do not want to completely remove whitespace
nodes that are siblings of an expansion.
For example, the following template
```html
<div>
<strong>items left<strong> {count, plural, =1 {item} other {items}}
</div>
```
was being collapsed to
```html
<div><strong>items left<strong>{count, plural, =1 {item} other {items}}</div>
```
which results in the text looking like
```
items left4
```
instead it should be collapsed to
```html
<div><strong>items left<strong> {count, plural, =1 {item} other {items}}</div>
```
which results in the text looking like
```
items left 4
```
---
**Analysis of the code and manual testing has shown that this does not cause
the generated ids to change, so there is no breaking change here.**
PR Close#31962
Pete Bacon Darwin
Misko Hevery
Pawel Kozlowski