Add Excel Export and CSV Delimiter Options

[Valeonl]

Problem
Currently, the system only exports tables to CSV format, which causes issues:

• Data formatting is lost when opening in Excel (leading zeros removed, dates corrupted)
• No cell styling, column widths, or visual formatting
• Comma separators cause problems in regions that use commas as decimal points

Solution

1. Add Excel (.xlsx) export option to preserve:

   • Original data formatting (leading zeros, exact dates)
   • Basic styling (bold headers, column widths)

2. Add CSV delimiter selection as minimum solution:

   • Choose separator: comma, semicolon, tab, pipe
   • Configure text qualifier

Alternatives Considered

• Only adding CSV delimiter options - solves regional issues but not Excel formatting problems
• PDF export - preserves visual layout but not editable data

Context
Most users expect exported tables to look the same as in the web interface and open properly in Excel without manual adjustments. XLSX is the standard for spreadsheet data and solves all CSV-related issues.