Add new page module and services; refactor existing entities

- Introduced a new page module with associated services.
- Refactored TypeORM entities in user and workspace modules.

server/src/core/page/page.controller.ts

@@ -0,0 +1,23 @@
+import { Controller, Post, Body, Delete, Get, Param } from "@nestjs/common";
+import { PageService } from './page.service';
+import { CreatePageDto } from './dto/create-page.dto';
+
+@Controller('page')
+export class PageController {
+  constructor(private readonly pageService: PageService) {}
+
+  @Post('create')
+  async create(@Body() createPageDto: CreatePageDto) {
+    return this.pageService.create(createPageDto);
+  }
+
+  @Get('page/:id')
+  async getPage(@Param('id') pageId: string) {
+    return this.pageService.findById(pageId);
+  }
+
+  @Delete('delete/:id')
+  async delete(@Param('id') pageId: string) {
+    await this.pageService.delete(pageId);
+  }
+}