master data initialization handling

- progress circle centered

Pages/IndexPage.razor

 @page "/"
 @using CaritasPWA.Shared.Services;
+@using System.Threading;
 @inject NavigationManager NavigationManager;
 @inject AppState AppState;
 @inject IStringLocalizer<Resources> i18n
     <div class="row align-items-center justify-content-center vw-100 h-25">
         <div>
             @if (showProgressCircle) {
-                <MatProgressCircle Indeterminate="true" Size="MatProgressCircleSize.Large" Style="padding-left:1.2rem" />
+                <div style="width:48px;margin:0 auto;">
+                    <MatProgressCircle Indeterminate="true" Size="MatProgressCircleSize.Large" />
+                </div>
                 <h6 style="font-style:italic;padding-bottom:1em">@i18n["Info.Masterdata.Initializing"]</h6>
             }
         </div>
             Console.WriteLine("First activation");
             showProgressCircle = true;
             StateHasChanged();
-            //await MasterDataService.SynchronizeMasterdata();
-            //showProgressCircle = false;
             try {
                 await MasterDataService.SynchronizeMasterdata();
             } catch (Exception ex) {

wwwroot/service-worker.js

 // This is because caching would make development more difficult (changes would not
 // be reflected on the first load after each change).
 
-const staticCacheName = 'site-static-v1';
+const staticCacheName = 'site-static-v1'; // IMPORTANT: CHANGE THE VERSION IN THIS NAME EVERY TIME THE APP IS DEPLOYED ON SERVER WITH CHANGES!!!
 const assets = [
     './',
     '/index.html',
 // activate event
 self.addEventListener('activate', event => {
     //delete any caches that aren't in expectedCaches
-    //which will get rid of site-static-v1
+    //which will get rid of site-static-v<n-1>
     event.waitUntil(
         caches.keys().then(keys => Promise.all(
             keys.map(key => {