Refactor project structure and enhance UI styling

[jaybarden1]

Description

This pull request includes the following changes:

• Added basic CSS styles and favicon for the AStar.Dev.Web project.
• Applied initial styling and configuration adjustments for the AStar.Dev.Web project.
• Moved and cleaned up the project structure by removing the AStar.Web.Web project and migrating its content to AStar.Web.

Checklist

• Tests have been added or updated (if applicable)
• Documentation has been updated (if applicable)
• Changes have been reviewed for coding standards and best practices
• Relevant issues have been linked or closed