store treetable column sort on adjustment, and restore on wallet load

src/main/java/com/sparrowwallet/drongo/wallet/SortDirection.java

@@ -0,0 +1,5 @@
+package com.sparrowwallet.drongo.wallet;
+
+public enum SortDirection {
+    ASCENDING, DESCENDING
+}

src/main/java/com/sparrowwallet/drongo/wallet/WalletTable.java

@@ -3,10 +3,21 @@ package com.sparrowwallet.drongo.wallet;
 public class WalletTable extends Persistable {
     private final TableType tableType;
     private final Double[] widths;
+    private final int sortColumn;
+    private final SortDirection sortDirection;
 
-    public WalletTable(TableType tableType, Double[] widths) {
+    public WalletTable(TableType tableType, Double[] widths, int sortColumn, SortDirection sortDirection) {
         this.tableType = tableType;
         this.widths = widths;
+        this.sortColumn = sortColumn;
+        this.sortDirection = sortDirection;
+    }
+
+    public WalletTable(TableType tableType, Double[] widths, Sort sort) {
+        this.tableType = tableType;
+        this.widths = widths;
+        this.sortColumn = sort.sortColumn;
+        this.sortDirection = sort.sortDirection;
     }
 
     public TableType getTableType() {
@@ -17,6 +28,18 @@ public class WalletTable extends Persistable {
         return widths;
     }
 
+    public int getSortColumn() {
+        return sortColumn;
+    }
+
+    public SortDirection getSortDirection() {
+        return sortDirection;
+    }
+
+    public Sort getSort() {
+        return new Sort(sortColumn, sortDirection);
+    }
+
     @Override
     public final boolean equals(Object o) {
         if(this == o) {
@@ -33,4 +56,6 @@ public class WalletTable extends Persistable {
     public int hashCode() {
         return tableType.hashCode();
     }
+
+    public record Sort(int sortColumn, SortDirection sortDirection) {}
 }