Fixes following code smell reported by SonarQube:

1) Replace this if-then-else flow by a single return statement
 2) Remove the unnecessary boolean literals.

web/pgadmin/static/js/SchemaView/base_schema.ui.js

@@ -139,18 +139,12 @@ export default class BaseUISchema {
 
   /* Check if node in catalog */
   inCatalog() {
-    if(this.nodeInfo && 'catalog' in this.nodeInfo) {
-      return true;
-    }
-    return false;
+    return this.nodeInfo && 'catalog' in this.nodeInfo;
   }
 
   /* Check readonly on the basis of new state */
   isReadOnly(state) {
-    if(!this.isNew(state)) {
-      return true;
-    }
-    return false;
+    return !this.isNew(state);
   }
 
   /* Get the server version */

web/pgadmin/static/js/codemirror/addon/fold/pgadmin-sqlfoldcode.js

@@ -117,10 +117,7 @@
     //this reg will check the token should be in format as - IF condition or IF(condition)
     let reg = `\\b\\${startToken}\\s*\\(\\w*\\)(?!\\w)|\\b\\${startToken}\\(\\w*\\)(?!\\w)|\\b\\${startToken}\\s*(?!\\w)`;
     let regex = RegExp(reg, 'g');
-    if(regex.exec(text) !== null) {
-      return true;
-    }
-    return false;
+    return regex.exec(text) !== null;
   }
 
   CodeMirror.registerHelper('fold', 'sql', function(cm, start) {

web/pgadmin/static/js/components/PgTable.jsx

@@ -347,10 +347,7 @@ export default function PgTable({ columns, data, isSelectRow, caveTable=true, sc
     setHiddenColumns(
       columns
         .filter((column) => {
-          if (column.isVisible === undefined || column.isVisible === true) {
-            return false;
-          }
-          return true;
+          return !(column.isVisible === undefined || column.isVisible === true);
         }
         )
         .map((column) => column.accessor)