[7.5] [Header] Force line-break if username is a solid long st… (#53581)

Fixes #50059 by adding a break-word utility class to the username.

Co-authored-by: Caroline Horn <549577+cchaos@users.noreply.github.com>

Author: legrego

x-pack/legacy/plugins/security/public/views/nav_control/nav_control_component.js

@@ -80,7 +80,7 @@ export class SecurityNavControl extends Component {
 
             <EuiFlexItem>
               <EuiText>
-                <p>{name}</p>
+                <p className="eui-textBreakWord">{name}</p>
               </EuiText>
 
               <EuiSpacer size="m" />