Add pagination sort by column (#48)

## Purpose

Fixes [issues/9743](https://roadmap.entgra.net/issues/9743)

## Improvement

Sort in ASC OR DESC on pagination requested by column name

Co-authored-by: Rushdi <rushdi@entgra.io>
Co-authored-by: Pahansith Gunathilake <pahansith@entgra.io>
Reviewed-on: community/device-mgt-core#48
Co-authored-by: Rushdi Mohamed <rushdi@entgra.io>
Co-committed-by: Rushdi Mohamed <rushdi@entgra.io>

components/device-mgt/org.wso2.carbon.device.mgt.common/src/main/java/org/wso2/carbon/device/mgt/common/PaginationRequest.java

@@ -44,6 +44,7 @@ public class PaginationRequest {
     private Map<String, Object> property = new HashMap<>();
     private List<String> statusList = new ArrayList<>();
     private OperationLogFilters operationLogFilters = new OperationLogFilters();
+    private List<SortColumn> sortColumn = new ArrayList<>();
     public OperationLogFilters getOperationLogFilters() {
         return operationLogFilters;
     }
@@ -172,11 +173,38 @@ public class PaginationRequest {
         this.filter = filter;
     }
 
+    public void setSortColumn(List<SortColumn> sortColumn) { this.sortColumn = sortColumn; }
+
+    public List<SortColumn> getSortColumn() { return sortColumn; }
+
+    /**
+     * Convert SortColumns field parameter and splitting string into columnName and sortType
+     *
+     * @param sortColumns which is separated by a colon(:) and first will be the columnNane and the second will be type ASC or DESC,
+     *                    if there is no colon(:) detected, ASC will be default
+     *                    (Ex: sort=col1:ASC&sort=col2:DESC, sort=col1&sort=col2:DESC)
+     * @return sortColumnList as a list of sortColumn
+     */
+    public void setSortColumns(List<String> sortColumns) {
+        List<SortColumn> sortColumnList = new ArrayList<>();
+        SortColumn sortColumn;
+        String[] sorting;
+        for (String sortBy: sortColumns) {
+            sortColumn = new SortColumn();
+            sorting = sortBy.split(":");
+            sortColumn.setName(sorting[0]);
+            sortColumn.setType(sorting.length >= 2 && (sorting[1].equalsIgnoreCase("desc"))
+                    ? SortColumn.types.DESC : SortColumn.types.ASC);
+            sortColumnList.add(sortColumn);
+        }
+        setSortColumn(sortColumnList);
+    }
+
     @Override
     public String toString() {
         return "Device type '" + this.deviceType + "' Device Name '" + this.deviceName + "' row count: " + this.rowCount
                 + " Owner role '" + this.ownerRole + "' owner pattern '" + this.ownerPattern + "' ownership "
                 + this.ownership + "' Status '" + this.statusList + "' owner '" + this.owner + "' groupId: " + this.groupId
-                + " start index: " + this.startIndex;
+                + " start index: " + this.startIndex + ", SortColumns: " + this.sortColumn;
     }
 }

components/device-mgt/org.wso2.carbon.device.mgt.common/src/main/java/org/wso2/carbon/device/mgt/common/SortColumn.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2023, Entgra (pvt) Ltd. (https://entgra.io) All Rights Reserved.
+ *
+ * Entgra (Pvt) Ltd. licenses this file to you under the Apache License,
+ * Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.wso2.carbon.device.mgt.common;
+
+/**
+ * This class holds required parameters for a querying a sort by column in pagination.
+ *
+ */
+public class SortColumn {
+    String name;
+    SortColumn.types type;
+
+    public enum types {
+        ASC, DESC
+    }
+
+    /**
+     * ColumnName setter method
+     * @param name of the column
+     */
+    public void setName(String name) { this.name = name; }
+
+    /**
+     * get the name of the column
+     * @return name
+     */
+    public String getName() { return name; }
+
+    /**
+     * Column sort type
+     * @param type of sort as ASC or DESC
+     */
+    public void setType(SortColumn.types type) { this.type = type; }
+
+    /**
+     * get column sort type
+     * @return type of sort
+     */
+    public SortColumn.types getType() { return type; }
+
+    @Override
+    public String toString() {
+        return "Column Name - " + this.name + ", Type - " + this.type ;
+    }
+
+}