Enhance image size validation messages

[kartik-v]

Change msgImageWidthSmall, msgImageHeightSmall, msgImageWidthLarge, msgImageHeightLarge defaults to include the detected image dimension. New default settings of the above properties will be:

{
  msgImageWidthSmall: 'Width of image file "{name}" must be at least <b>{size} px</b> (detected <b>{dimension} px</b>).',
  msgImageHeightSmall: 'Height of image file "{name}" must be at least <b>{size} px</b> (detected <b>{dimension} px</b>).',
  msgImageWidthLarge: 'Width of image file "{name}" cannot exceed <b>{size} px</b> (detected <b>{dimension} px</b>).',
  msgImageHeightLarge: 'Height of image file "{name}" cannot exceed <b>{size} px</b> (detected <b>{dimension} px</b>).',
}