Enhance Entry TOC plugin: childrens, numbering, and blockTitleFields

[SaraBabic]

This PR introduces several improvements to the Entry TOC plugin:

1. Fixed accordion item class names

   • Corrected previously mistyped class names for proper styling.

2. Support for nested Neo blocks (children)

   • TOC now recursively renders child blocks, maintaining hierarchy.

3. Optional numbering for blocks

   • Blocks can now be numbered (1, 1.1, 1.1.1…) based on the numbering config option.
   • Default behavior remains bullet list if numbering is false.

4. Display additional block title fields

   • Configurable via blockTitleFields (e.g., ['title', 'headline'])
   • Only the first available field value is displayed in parentheses next to the block type.
   • Fields not defined or empty are ignored.