fix: Improve login, server selection and proxy configuration (#2511)

No potentially malicious URLs referenced in markdown; added
servers stays in server selector list; the currently active server
is visible on the bottom right of smaller screens; a proxy configuration
can be provided now and works; a trailing slash in the added server
is no problem anymore, because it's removed.

FIXES: WEB-193

src/app/shared/footer/footer.component.html

@@ -1,4 +1,4 @@
-<div class="layout-column m-b-20" ngClass="{{ styleClass }}" id="footer" *ngIf="displayBackEndInfo">
+<div class="layout-column m-b-20 f12" ngClass="{{ styleClass }}" id="footer" *ngIf="displayBackEndInfo">
   <mat-divider class="divider align-center"></mat-divider>
   <div class="layout-column m-b-20 content-wrapper footer-center">
     <table class="versions">
@@ -15,8 +15,9 @@
         </td>
       </tr>
       <tr *ngIf="displayBackEndInfo">
-        <td colspan="2" class="center footer-content">
-          <b>{{ server }}</b>
+        <td class="footer-content">{{ 'labels.inputs.Server' | translate }}</td>
+        <td class="right footer-content">
+          {{ server }}
         </td>
       </tr>
       <tr *ngIf="isBusinessDateDefined">