feat: implement back button for banner

This button is intended to bring the user all the way back to the specified dashboard. Another could be created to exit the form, but I don't think that's needed for now.

src/pages/provider_portal.rs

@@ -20,7 +20,7 @@ pub fn ProviderPortal() -> impl IntoView {
     });
     
     view! {
-        <Banner title="Provider Dashboard" logo="PHS_Stacked_Acronym.png" path="/" />
+        <Banner title="Provider Dashboard" logo="PHS_Stacked_Acronym.png" />
         <AuthLoaded fallback=Loading>
             <Authenticated unauthenticated=UnauthenticatedPage>
                 <div class="mx-auto px-6">