Move back-button to login view

Signed-off-by: RMidhunSuresh <rmidhunsuresh@gmail.com>

src/domain/login/LoginViewModel.js

@@ -42,6 +42,7 @@ export class LoginViewModel extends ViewModel {
     get defaultHomeServer() { return this._homeserver; }
     get errorMessage() { return this._errorMessage; }
     get showHomeserver() { return !this._completeSSOLoginViewModel; }
+    get cancelUrl() { return this.urlCreator.urlForSegment("session"); }
 
     async _createViewModels(homeserver) {
         if (this._loginToken) {

src/domain/login/PasswordLoginViewModel.js

@@ -30,7 +30,6 @@ export class PasswordLoginViewModel extends ViewModel {
     }
 
     get loadViewModel() {return this._loadViewModel; }
-    get cancelUrl() { return this.urlCreator.urlForSegment("session"); }
 
     get isBusy() {
         if (!this._loadViewModel) {

src/platform/web/ui/css/login.css

@@ -74,11 +74,12 @@ limitations under the License.
 .StartSSOLoginView {
     display: flex;
     flex-direction: column;
+    padding: 0 0.4em 0;
 }
 
 .StartSSOLoginView_button {
     flex: 1;
-    margin-top: 10px;
+    margin-top: 12px;
 }
 
 .LoginView_separator {

src/platform/web/ui/css/themes/element/theme.css

@@ -228,6 +228,11 @@ a.button-action {
     border-radius: 8px;
 }
 
+.LoginView_back {
+    background-image: url("./icons/chevron-left.svg");
+    background-color: transparent;
+}
+
 .LoginView_separator {
     font-weight: 500;
     font-size: 1.5rem;

src/platform/web/ui/login/LoginView.js

@@ -30,6 +30,7 @@ export class LoginView extends TemplateView {
             });
 
         return t.div({className: "PreSessionScreen"}, [
+            t.a({className: "button-utility LoginView_back", href: vm.cancelUrl}),
             t.div({className: "logo"}),
             t.h1([vm.i18n`Sign In`]),
             t.mapView(vm => vm.completeSSOLoginViewModel, vm => vm ? new CompleteSSOView(vm) : null),

src/platform/web/ui/login/PasswordLoginView.js

@@ -45,10 +45,6 @@ export class PasswordLoginView extends TemplateView {
                 t.div({ className: "form-row" }, [t.label({ for: "password" }, vm.i18n`Password`), password]),
                 t.mapView(vm => vm.loadViewModel, loadViewModel => loadViewModel ? new SessionLoadStatusView(loadViewModel) : null),
                 t.div({ className: "button-row" }, [
-                    t.a({
-                        className: "button-action secondary",
-                        href: vm.cancelUrl
-                    }, [vm.i18n`Go Back`]),
                     t.button({
                         className: "button-action primary",
                         type: "submit"