The TextEdit component failed to recognize consecutive '\r\n' characters correctly

The TextEdit component failed to recognize consecutive '\r\n' characters correctly

**Describe the bug**

I found that when I give a string with '\r\n\r\n' to make TextEdit display, there is something wrong with the display. For example it looks like there is one line missing.When I press Key::Down, I can't reach the last '\r\n', but whether I get a new line can be displayed.

**To Reproduce**
Steps to reproduce the behavior:
1. Go to the CodeEditor,modify the code value to end with '\r\n\r\n'
2. Click on the keyboard down button
3.

**Expected behavior**

**Screenshots**

**Desktop (please complete the following information):**
- OS: Windows11
- Browser :chrome
- Version 22

**Additional context**
Modified value:
code: "// A very simple example\n\
fn main() {\n\
\tprintln!(\"Hello world!\");\n\
}\r\n\r\n"
.into(),

Start with the TextEdit component and reproduce the issue through CodeEditor using a value ending in consecutive '\r\n' characters. Inspect how Key::Down handles the final empty lines and verify that every newline is reachable and displayed correctly, including the trailing blank line.

Written by the indexing model from the issue text.