feat: table background color, cell header and align (#1352)

* feat: add toggle header cell button to table cell menu

Added ability to toggle header cells directly from the table cell menu. This enhancement includes:
- New toggle header cell button with IconTableRow icon
- Consistent UI/UX with existing table menu patterns
- Proper internationalization support

* fix: typo in aria-label for toggle header cell button

* feat: add table cell background color picker

- Extended TableCell and TableHeader to support backgroundColor attribute
- Created TableBackgroundColor component with 21 color options
- Integrated color picker into table cell menu using Mantine UI
- Added support for both regular cells and header cells
- Updated imports to use custom TableHeader from @docmost/editor-ext

* feat: add text alignment to table cell menu

- Created TableTextAlignment component with left, center, and right alignment options
- Integrated alignment selector into table cell menu
- Shows current alignment icon in the button
- Displays checkmark next to active alignment in dropdown

* background colors

* table background color in dark mode

* add bg color name

* rename color attribute

* increase minimum table width

apps/client/src/features/editor/extensions/extensions.ts

@@ -11,7 +11,6 @@ import { Typography } from "@tiptap/extension-typography";
 import { TextStyle } from "@tiptap/extension-text-style";
 import { Color } from "@tiptap/extension-color";
 import Table from "@tiptap/extension-table";
-import TableHeader from "@tiptap/extension-table-header";
 import SlashCommand from "@/features/editor/extensions/slash-command";
 import { Collaboration } from "@tiptap/extension-collaboration";
 import { CollaborationCursor } from "@tiptap/extension-collaboration-cursor";
@@ -25,6 +24,7 @@ import {
   MathInline,
   TableCell,
   TableRow,
+  TableHeader,
   TrailingNode,
   TiptapImage,
   Callout,