Defect2271490 (#1474)

* arialabel has been added to close button of invitational youtube video

* heading role has been addedd and tag has been changed to h1

* outline has been restored to choose columns link in entities page

* header text color changed to meet luminosity ratio requirement

* capacity calculator link has been added with underline on focus

* add property is readout twice while using screenreader

* arialabel added to the add property button

* screenreader content changed to announce the entire alert

* alert message is partially readout on error

* Update fulldatatables.less

* Update queryBuilder.less

* Update TableEntity.tsx

* Update ThroughputInput.less

* Update ThroughputInput.tsx

* Update ThroughputInput.test.tsx.snap

* Update NewVertexComponent.tsx

* Update PanelInfoErrorComponent.tsx

* Update AddTableEntityPanel.tsx

* Update AddTableEntityPanel.test.tsx.snap

* Update SplashScreen.tsx

* Update QuickstartCarousel.tsx

* Update RightPaneForm.tsx

* Update fulldatatables.less

src/Explorer/Panes/PanelInfoErrorComponent.tsx

@@ -32,14 +32,8 @@ export const PanelInfoErrorComponent: React.FunctionComponent<PanelInfoErrorProp
   return (
     <Stack className="panelInfoErrorContainer" horizontal verticalAlign="center">
       {icon}
-      <span className="panelWarningErrorDetailsLinkContainer">
-        <Text
-          role="alert"
-          aria-live="assertive"
-          aria-label={message}
-          className="panelWarningErrorMessage"
-          variant="small"
-        >
+      <span className="panelWarningErrorDetailsLinkContainer" role="alert" aria-live="assertive">
+        <Text aria-label={message} className="panelWarningErrorMessage" variant="small">
           {message}
           {link && linkText && (
             <Link target="_blank" href={link}>