[Bug] cursorHeight

### Bug Description

The cursor height is not constant, and the height of the cursor is smaller for space character than others. I see that there is an unexposed field "cursorHeight" somewhere in the code.

### How to Reproduce

Just construct a AppFlowyEditor and type "Hello, World," you will see that the cursor height is less when the cursor is at the space between two words.

### Expected Behavior

The cursor height should remain constant.

### Operating System

macOS

### AppFlowy Editor Version(s)

latest stable

### Screenshots

big:

small (space):

### Additional Context

_No response_