Provide Table Upload Functionality

[kaanozgen12]

As an Event Organizer, I want to import predefined seat plan templates (e.g., Excel format), so that I can quickly create layouts based on standard setups.

Acceptance Criteria:

• System accepts uploads in a specific format (e.g., Excel with table names and chair counts).
• Uploaded data generates tables with chairs auto-arranged in the center of the canvas with appropriate initial spacing in between them.
• Imported elements can be fully edited post-import.