Title: Keep [lineList] inside in SunEditor

Description:
Currently, SunEditor moves the placeholder [lineList] outside of the <tbody> when editing the content. This causes an issue when trying to later replace [lineList] with dynamic content inside a table.

Problem Example:
Before editing in SunEditor:

<table>
  <tbody>
     [lineList]
  </tbody>
</table>

After editing in SunEditor:

<p>     [lineList]  </p>
<table>
  <tbody></tbody>
</table>

Expected Behavior: SunEditor should allow [lineList] to remain inside without moving it outside the table.

Steps to Reproduce:

Insert a table in SunEditor.
Add [lineList] inside the .
Edit or save the content.
Observe that [lineList] is moved outside of .

Environment:

SunEditor Version: 2.47.4
Possible Solution: Allow SunEditor to preserve placeholders inside without removing or moving them outside the table.

Additional Notes: This issue affects the ability to handle dynamic content inside tables and may impact customization of the HTML generated by SunEditor.

Thank you for your attention and any help in resolving this issue.