Remove obsolete styles from navigationBar.less

Addresses #9283

.navbarMenubarBlockContainer (introduced with f2426f1#diff-303f0b6a297506f2cc18bf7b4cb370c5R789, which no longer exists on the master branch.)

.inputbar-wrapper (introduced with 0e57690#diff-02c4b23ad267fe636760179e32fa29ceR141 with no clear reason. Since .inputbar-wrapper has not been used, it can be removed safely.)

less/navigationBar.less

@@ -374,10 +374,6 @@
   overflow: visible;
   white-space: nowrap;
 }
-.navbarMenubarBlockContainer {
-  display: block;
-  width: 100%;
-}
 
 // Window Caption Buttons (for use w/ slim titlebar)
 .windowCaptionButtons {
@@ -841,14 +837,6 @@
        user-select: none;
     }
 
-    .inputbar-wrapper {
-      display: flex;
-      flex: 1 1 0;
-      border-radius: 4px;
-      align-items: center;
-      justify-content: center;
-    }
-
     input {
       border: none;
       box-sizing: border-box;