BaseDataWindow: Remove transactions inside *Save() functions to avoid nesting them

Elwig/Windows/BaseDataWindow.xaml.Branch.cs

@@ -41,7 +41,6 @@ namespace Elwig.Windows {
             if (!_branchChanged || _branchList == null || _branches == null || _branchIds == null)
                 return;
 
-            var tx = await ctx.Database.BeginTransactionAsync();
             var deleteZwstIds = _branches.Where(b => b.Value == null).Select(b => b.Key).ToList();
             await ctx.Branches.Where(b => deleteZwstIds.Contains(b.ZwstId)).ExecuteDeleteAsync();
 
@@ -62,7 +61,6 @@ namespace Elwig.Windows {
                 ctx.Add(branch);
             }
             await ctx.SaveChangesAsync();
-            await tx.CommitAsync();
         }
 
         private void BranchList_SelectionChanged(object? sender, SelectionChangedEventArgs? evt) {

Elwig/Windows/BaseDataWindow.xaml.WineAttr.cs

@@ -41,7 +41,6 @@ namespace Elwig.Windows {
             if (!_attrChanged || _attrList == null || _attrs == null || _attrIds == null)
                 return;
 
-            using var tx = await ctx.Database.BeginTransactionAsync();
             var deleteAttrIds = _attrs.Where(a => a.Value == null).Select(a => a.Key).ToList();
             await ctx.WineAttributes.Where(a => deleteAttrIds.Contains(a.AttrId)).ExecuteDeleteAsync();
             foreach (var (attr, old) in _attrIds) {
@@ -63,7 +62,6 @@ namespace Elwig.Windows {
                 ctx.Add(attr);
             }
             await ctx.SaveChangesAsync();
-            await tx.CommitAsync();
         }
 
         private void WineAttributeList_SelectionChanged(object? sender, SelectionChangedEventArgs? evt) {

Elwig/Windows/BaseDataWindow.xaml.WineCult.cs

@@ -41,7 +41,6 @@ namespace Elwig.Windows {
             if (!_cultChanged || _cultList == null || _cults == null || _cultIds == null)
                 return;
 
-            using var tx = await ctx.Database.BeginTransactionAsync();
             var deleteCultIds = _cults.Where(c => c.Value == null).Select(c => c.Key).ToList();
             await ctx.WineCultivations.Where(c => deleteCultIds.Contains(c.CultId)).ExecuteDeleteAsync();
             foreach (var (cult, old) in _cultIds) {
@@ -62,7 +61,6 @@ namespace Elwig.Windows {
                 ctx.Add(cult);
             }
             await ctx.SaveChangesAsync();
-            await tx.CommitAsync();
         }
 
         private void WineCultivationList_SelectionChanged(object? sender, SelectionChangedEventArgs? evt) {