[Bug] cursor position

### Bug Description


### How to Reproduce

ctrl + shift + > to select the sentence
press the down arrow

### Expected Behavior

un-select the text
the cursor is in the end of the current selection if there isn't a line inserted by Enter
the cursor is in the beginning of the next line (block) if there is an empty line
the cursor is in the end of the next text block if there is another non-empty line

FYI: check how google docs handles it

### Operating System

Windows 11

### AppFlowy Version(s)

v0.2.2

### Screenshots

_No response_

### Additional Context

_No response_