Bug: Decorator block nodes selection selects all nodes or nothing

Lexical version: 0.7.6

## Steps To Reproduce

1. Add a few decorator nodes (e.g. tweets) next to each other inside a text
2. Start selecting text before the nodes
3. Nodes do not become selected until the text after the nodes is selected (same for de-selection)

## The current behavior

https://user-images.githubusercontent.com/1575198/213175139-d1610d19-ad6e-4e8a-8ddc-2bd93d273bf2.mov

**Note:** This is not an issue with the horizontal rule nodes
https://user-images.githubusercontent.com/1575198/213175349-68ec35f0-7d92-4deb-8e12-cfb6a99d3efa.mov
P.s. on this video you can see a flickering issue, which is a separate one https://github.com/facebook/lexical/issues/3741