WIP Add Win10 and Fluent TextBox styles

[punker76]

Describe the changes you have made to improve this project

• Add new attached property ControlsHelper.DisabledBorderBrush
• Add new TextBox style values
  • TextControlBorderThemeThickness
  • TextControlThemePadding
  • TextControlBorderThemeThicknessFocused
  • TextControlPlaceholderMargin
• Add new Win10 style: MahApps.Styles.TextBox.Win10
• Add new Fluent style: MahApps.Styles.TextBox.Fluent
• Add new brushes:
  • MahApps.Brushes.TextControl.Background
  • MahApps.Brushes.TextControl.BackgroundPointerOver
  • MahApps.Brushes.TextControl.BackgroundFocused
  • MahApps.Brushes.TextControl.BackgroundDisabled
  • MahApps.Brushes.TextControl.BorderBrush
  • MahApps.Brushes.TextControl.BorderBrushPointerOver
  • MahApps.Brushes.TextControl.BorderBrushFocused
  • MahApps.Brushes.TextControl.BorderBrushDisabled
  • MahApps.Brushes.TextControl.Foreground
  • MahApps.Brushes.TextControl.ForegroundPointerOver
  • MahApps.Brushes.TextControl.ForegroundFocused
  • MahApps.Brushes.TextControl.ForegroundDisabled
  • MahApps.Brushes.TextControl.PlaceholderForeground
  • MahApps.Brushes.TextControl.PlaceholderForegroundPointerOver
  • MahApps.Brushes.TextControl.PlaceholderForegroundFocused
  • MahApps.Brushes.TextControl.PlaceholderForegroundDisabled
  • MahApps.Brushes.TextControl.HeaderForeground
  • MahApps.Brushes.TextControl.HeaderForegroundDisabled
  • MahApps.Brushes.TextControl.SelectionHighlightColor
  • MahApps.Brushes.TextControl.ButtonBackground
  • MahApps.Brushes.TextControl.ButtonBackgroundPointerOver
  • MahApps.Brushes.TextControl.ButtonBackgroundPressed
  • MahApps.Brushes.TextControl.ButtonBorderBrush
  • MahApps.Brushes.TextControl.ButtonBorderBrushPointerOver
  • MahApps.Brushes.TextControl.ButtonBorderBrushPressed
  • MahApps.Brushes.TextControl.ButtonForeground
  • MahApps.Brushes.TextControl.ButtonForegroundPointerOver
  • MahApps.Brushes.TextControl.ButtonForegroundPressed

BREAKING CHANGE: change background for dark theme

Change the dark theme background from #FF252525 to #FF141414.

Closed Issues

Closes #3209

[JackDjTom]

Any idea when this issue will be fixed and version 3.0 will be released approximately?