Sampath accessibility sev 2 (#1400)

* autoscale and manual radiobuutton fixes

* alt text attribute for images

* Revert "alt text attribute for images"

This reverts commit 5a660551c6.

* alt text for decorative images

* sev2 accessibilitydefects in data explorer

* Revert "sev2 accessibilitydefects in data explorer"

This reverts commit b84d5b572c.

* Sev2 accessibilitydefects

* Revert "Sev2 accessibilitydefects"

This reverts commit a4e60f106c.

* accessibilitydefects-data explorer

* Remove extra white space

---------

Co-authored-by: Victor Meng <vimeng@microsoft.com>

src/Explorer/Graph/GraphExplorerComponent/GraphVizComponent.tsx

@@ -40,6 +40,7 @@ export class GraphVizComponent extends React.Component<GraphVizComponentProps> {
             {/* svg load more icon inlined as-is here: remove the style="fill:#374649;" so we can override it */}
             <svg
               role="img"
+              aria-label="graph"
               version="1.1"
               xmlns="http://www.w3.org/2000/svg"
               xmlnsXlink="http://www.w3.org/1999/xlink"
@@ -135,6 +136,7 @@ export class GraphVizComponent extends React.Component<GraphVizComponentProps> {
           <g id="triangleRight">
             <svg
               role="img"
+              aria-label="graph"
               version="1.1"
               id="Layer_1"
               xmlns="http://www.w3.org/2000/svg"

src/Explorer/Graph/GraphExplorerComponent/MiddlePaneComponent.tsx

@@ -17,19 +17,19 @@ export class MiddlePaneComponent extends React.Component<MiddlePaneComponentProp
       <div className="middlePane">
         <div className="graphTitle">
           <span className="paneTitle">Graph</span>
-          <span
+          <button
+            style={{ border: "none", background: "none" }}
             className="graphExpandCollapseBtn pull-right"
             onClick={this.props.toggleExpandGraph}
             role="button"
             aria-expanded={this.props.isTabsContentExpanded}
             aria-name="View graph in full screen"
-            tabIndex={0}
           >
             <img
               src={this.props.isTabsContentExpanded ? CollapseArrowIcon : ExpandIcon}
               alt={this.props.isTabsContentExpanded ? "collapse graph content" : "expand graph content"}
             />
-          </span>
+          </button>
         </div>
         <div className="maingraphContainer">
           <GraphVizComponent forceGraphParams={this.props.graphVizProps.forceGraphParams} />