set the correct min-width to resizer and its parent element (#9600)

frontend/src/app/shared/components/resizer/resizer/wp-resizer.component.ts

@@ -69,7 +69,7 @@ export class WpResizerDirective extends UntilDestroyedMixin implements OnInit, A
   private resizer:HTMLElement;
 
   // Min-width this element is allowed to have
-  private elementMinWidth = 530;
+  private elementMinWidth = 645;
 
   public moving = false;
 

frontend/src/global_styles/layout/work_packages/_details_view.sass

@@ -49,8 +49,8 @@ body.router--work-packages-partitioned-split-view-new
   height: 100%
   position: relative
   width: 100%
-  // Min-width is actually 530px but the border already needs 2px
-  min-width: 528px
+  // Min-width is actually 645px but the border already needs 2px
+  min-width: 643px
 
   @media only screen and (max-width: 1280px)
     @at-root

frontend/src/global_styles/layout/work_packages/_full_view.sass

@@ -96,7 +96,7 @@
           line-height: calc(var(--work-package-details--tab-height) - 10px)
 
 .work-packages-full-view--split-right
-  min-width: 500px
+  min-width: 645px
   overflow-y: scroll
   overflow-x: auto
   position: relative