Accessibility issues (#598)

* Tooltip is added for the back button in the main window

* Scroll bar is getting overlap on the pane and text issue is fixed over all pages

* Automation Property added for the "source code" expander

Merge pull request #313 from MarkDHarper/1145041

Fix bug 1145041 by using a color with a higher contrast ratio for error text

Merge pull request #313 from MarkDHarper/1145041

Fix bug 1145041 by using a color with a higher contrast ratio for error text

Merge pull request #317 from microsoft/DataBindingDemo-AccessibilityF…

…ixes

Data binding demo accessibility fixes

Merge pull request #317 from microsoft/DataBindingDemo-AccessibilityF…

…ixes

Data binding demo accessibility fixes

Merge pull request #312 from MarkDHarper/1145048

Fix for 1145048 -- ensure that focus rectangle is visible

Merge pull request #312 from MarkDHarper/1145048

Fix for 1145048 -- ensure that focus rectangle is visible

Merge pull request #311 from MarkDHarper/1144932

Fix 1144932 by in ComboBoxSample by setting the tab-order to the logical order of operations

Merge pull request #310 from MarkDHarper/1144894

Fix for 1144894 remove confusing keyboard-focus behavior in CustomComboBox sample

DataBindingDemo fix 1144857 by making non-actionable content IsTabSto…

…p="False" on MainWindow and AddProductWindow (#308)

* Setting IsTabstop to false for portions of UI that are not meant to be interactive.

* Update AddProductWindow.xaml

Co-authored-by: Mark Harper (DEV) <[email protected]>