Improvements

• #5979 FileTarget - Improve file-wildcard for archive cleanup. (@snakefoot)
• #5980 FileTarget - Extend InternalLogger output with archive cleanup reason. (@snakefoot)
• #5981 FileTarget - Strict wildcard check only possible when single wildcard. (@snakefoot)
• #5987 FileTarget - Improve archive cleanup with dynamic seq-no. (@snakefoot)
• #5988 FileTarget - Avoid parsing archive sequence number when other digits. (@snakefoot)
• #5996 FileTarget - Improve fallback logic when missing file system birthtime. (@snakefoot)
• #5964 ColoredConsoleTarget - WholeWords should only highlight the word. (@snakefoot)
• #5967 ColoredConsoleTarget - Fixed boxing issue in ConsoleRowHighlightingRule. (@karpinsn)
• #5968 Simplify WithAutoFlush-method for fluent config API. (@snakefoot)
• #5970 Fix boxing for registration of builtin condition methods. (@snakefoot)
• #5977 ConditionExpression - Implicit operator with NotNullIfNotNull-attribute. (@GREsau)
• #5982 SimpleLayout - Implicit operator with NotNullIfNotNull-attribute. (@snakefoot)
• #5992 MessageLayoutRenderer - Handle Exception.ToString() can throw with AOT. (@snakefoot)