fix(idp): Remove kpop dependency

The built package (https://download.kopano.io/community/kapp:/kpop-2.7.2.tgz)
seems to be no longer available and upstream lico already switched away
from it quite a while ago.

Fixes: #2364

services/idp/src/App.jsx

@@ -2,10 +2,7 @@ import React, {ReactElement, Suspense, lazy, useState, useEffect} from 'react';
 import PropTypes from 'prop-types';
 
 import {MuiThemeProvider} from '@material-ui/core/styles';
-import {defaultTheme} from 'kpop/es/theme';
-
-import 'kpop/static/css/base.css';
-import 'kpop/static/css/scrollbar.css';
+import muiTheme from './theme';
 
 import Spinner from './components/Spinner';
 import * as version from './version';
@@ -52,7 +49,7 @@ const App = ({ bgImg }): ReactElement => {
                 className={`oc-login-bg ${bgImg ? 'oc-login-bg-image' : ''}`}
                 style={{backgroundImage: bgImg ? `url(${bgImg})` : undefined}}
             >
-                <MuiThemeProvider theme={defaultTheme}>
+                <MuiThemeProvider theme={muiTheme}>
                     <Suspense fallback={<Spinner/>}>
                         <LazyMain/>
                     </Suspense>

services/idp/src/app.css

@@ -1,4 +1,3 @@
-/* additional css on top of kpop */
 @font-face {
     font-family: OpenCloud;
     src: url('./fonts/OpenCloud500-Regular.woff2') format('woff2');
@@ -17,16 +16,25 @@
 html {
     font-feature-settings: "cv11";
     color: #20434f !important;
+    height: 100%;
 }
 
 body {
     font-family: OpenCloud, sans-serif;
+    height: 100%;
+    margin: 0;
+    padding: 0;
 }
 
 strong {
     font-weight: 600;
 }
 
+#root {
+  height: 100%;
+  display: flex;
+}
+
 .oc-font-weight-light {
     font-weight: 300;
 }