Fix dashboards listing table appearing distorted (#96371)

* fix CSS

* approx height calc to account for header div

public/app/features/plugins/admin/components/PluginDetailsBody.tsx

@@ -118,7 +118,7 @@ export function PluginDetailsBody({ plugin, queryParams, pageId }: Props): JSX.E
 
   if (pageId === PluginTabIds.USAGE && pluginConfig) {
     return (
-      <div>
+      <div className={styles.wrap}>
         <PluginUsage plugin={pluginConfig?.meta} />
       </div>
     );
@@ -140,6 +140,10 @@ export function PluginDetailsBody({ plugin, queryParams, pageId }: Props): JSX.E
 }
 
 export const getStyles = (theme: GrafanaTheme2) => ({
+  wrap: css({
+    width: '100%',
+    height: '50vh',
+  }),
   readme: css({
     '& img': {
       maxWidth: '100%',

public/app/features/plugins/admin/components/PluginDetailsPage.tsx

@@ -115,6 +115,7 @@ export const getStyles = (theme: GrafanaTheme2) => {
     // Needed due to block formatting context
     tabContent: css({
       paddingLeft: '5px',
+      width: '100%',
     }),
   };
 };

public/app/features/plugins/admin/components/PluginUsage.tsx

@@ -88,7 +88,7 @@ export const getStyles = (theme: GrafanaTheme2) => {
   return {
     wrap: css({
       width: '100%',
-      height: '100%',
+      height: '90%',
     }),
     info: css({
       paddingBottom: '30px',