Implement Multi-Workspace Schema for Newsletters, Websites, etc. (Security Focus)

[yacosta738]

This issue proposes a secure multi-workspace database schema in PostgreSQL to manage data for newsletters, websites, social media, and similar applications. The focus is on data isolation and user access control.

• [x] #297

  1. Define the workspaces table to store workspace information (name, owner, timestamps).
  2. Establish relationships with other tables using foreign keys.

• [x] #298

  1. Implement mechanisms to modify workspace details (name, owner).

• [x] #299

  1. Design a secure approach to delete workspaces, considering data integrity.