Improve PowerDistribution security with prepared statements and HTML escaping

[Emavero]

Summary

This pull request improves the security of the PowerDistribution component and the power alert email generation.

Changes

• Replaced string-concatenated SQL queries with PDO prepared statements to reduce the risk of SQL injection vulnerabilities.
• Updated the following methods:
  • CreatePDU
  • UpdatePDU
  • GetPDU
  • GetPDUbyPanel
  • GetPDUbyCabinet
  • SearchByPDUName
  • GetLastReading
  • GetWattageByDC
  • GetWattageByCabinet
  • LogManualWattage
  • UpdateStats
  • DeletePDU
• Escaped Name, Location, and Label using htmlspecialchars() in HTML power alert emails to prevent stored and reflected XSS issues.

Benefits

• Improved protection against SQL injection attacks.
• Reduced risk of XSS vulnerabilities in alert emails.
• Better alignment with secure coding practices and OWASP recommendations.

Testing

• Verified that existing PowerDistribution operations continue to function as expected.
• Verified that alert emails render correctly with escaped user-controlled values.