Made stdout window size nicely to fill the remaining height in the browser

Resolves PR feedback and takes care of #1575 along the way

awx/ui/client/src/standard-out/standard-out.block.less

@@ -43,7 +43,8 @@ standard-out-log {
     background-color: @default-secondary-bg;
     border-radius: 5px;
     min-height: 300px;
-    max-height: 900px;
+    max-height: 100vh;
+    height: ~"calc(100vh - 245px)";
     width: 100%;
 
     overflow: auto;