Chore: reorganize editor members

[CatHood0]

Description

As the title says, most of the files under the editor folder have been reorganized to be more readable and easily modified.

-- lib
|   |-- flutter_quill.dart
|   '-- src
|       |-- editor
|       |   |-- editor.dart
|       |   |-- raw_editor
|       |   |   |-- boundaries
|       |   |   |   |-- combinators
|       |   |   |   |   |-- quill_editor_collapsed_selection_boundary.dart
|       |   |   |   |   |-- quill_editor_mixed_boundary.dart
|       |   |   |   |   '-- quill_editor_text_expanded_boundary.dart
|       |   |   |   |-- editor_text_boundaries.dart
|       |   |   |   |-- quill_editor_text_boundary.dart
|       |   |   |   '-- text
|       |   |   |       |-- quill_editor_character_boundary.dart
|       |   |   |       |-- quill_editor_document_boundary.dart
|       |   |   |       |-- quill_editor_line_break_boundary.dart
|       |   |   |       |-- quill_editor_whitespace_boundary.dart
|       |   |   |       '-- quill_editor_word_boundary.dart
|       |   |   |-- editor_glyph_heights.dart
|       |   |   |-- editor_state.dart
|       |   |   |-- input
|       |   |   |   '-- raw_editor_state_text_input_client_mixin.dart
|       |   |   |-- raw_editor.dart
|       |   |   |-- raw_editor_state.dart
|       |   |   |-- render
|       |   |   |   |-- raw_editor_render_object.dart
|       |   |   |   '-- scribble_focusable.dart
|       |   |   '-- selection
|       |   |       '-- raw_editor_state_selection_delegate_mixin.dart
|       |   |-- render
|       |   |   |-- abstract_render_editor.dart
|       |   |   |-- quill_editor_text_selection_gestures.dart
|       |   |   |-- render_editable_container_box.dart
|       |   |   |-- render_editor.dart
|       |   |   '-- utils
|       |   |       |-- quill_vertical_caret_movement.dart
|       |   |       '-- render_editor_utils.dart
|       |   '-- widgets
|       |       |-- box.dart
|       |       |-- cursor.dart
|       |       |-- delegate.dart
|       |       |-- keyboard_listener.dart
|       |       |-- link.dart
|       |       |-- painters
|       |       |   |-- cursor_painter.dart
|       |       |   '-- floating_cursor_painter.dart
|       |       |-- proxies
|       |       |   |-- baseline_proxy.dart
|       |       |   |-- embed_proxy.dart
|       |       |   |-- proxy.dart
|       |       |   |-- render_paragraph_proxy.dart
|       |       |   '-- rich_text_proxy.dart
|       |       |-- styles
|       |       |   |-- block_styles.dart
|       |       |   |-- cursor_style.dart
|       |       |   |-- default_styles.dart
|       |       |   |-- inline_code_style.dart
|       |       |   '-- quill_styles.dart
|       |       '-- text
|       |           |-- block
|       |           |   |-- editable_block.dart
|       |           |   |-- render_editable_block.dart
|       |           |   '-- text_block.dart
|       |           |-- line
|       |           |   |-- editable_text_line.dart
|       |           |   |-- render_editable_line.dart
|       |           |   '-- text_line.dart
|       |           |-- selection
|       |           |   '-- text_selection.dart
|       |           '-- utils
|       |               '-- text_block_utils.dart

Type of Change

• [ ] ✨ Feature: New functionality without breaking existing features.
• [ ] 🛠️ Bug fix: Resolves an issue without altering current behavior.
• [x] 🧹 Refactor: Code reorganization, no behavior change.
• [ ] ❌ Breaking: Alters existing functionality and requires updates.
• [ ] 🧪 Tests: New or modified tests
• [ ] 📝 Documentation: Updates or additions to documentation.
• [x] 🗑️ Chore: Routine tasks, or maintenance.
• [ ] ✅ Build configuration change: Build/configuration changes.