V8.3

What's Changed

• Added test for OnEditCancelled event by @chuacw in #1326
• Fix missing scope and removed unused units by @chuacw in #1328
• Added tests for AddColumn, EditNode pass and failure by @chuacw in #1329
• Added a new OnDrawTextEx event, updated DoTextDrawing and new tests f… by @chuacw in #1331
• Changes file encoding from ANSI to UTF8 by @chuacw in #1333
• Fixes memory leaks in OLE demo by @chuacw in #1336
  Full Changelog: https://github.com/JAM-Software/Virtual-TreeView/milestone/33?closed=1