Refactor path handling in UI components

- Removed redundant folder and file opening methods from AiTabView and FaceAiTabView.
- Introduced PathPickerField control to streamline path selection and opening functionality across multiple views.
- Updated FaceAiTabView and GeneralTabView to utilize PathPickerField for source and destination path selection.
- Created PathShellService to encapsulate logic for opening paths in the file explorer.
- Simplified XAML structure by replacing manual grid definitions with PathPickerField components.
- Removed unused namespaces and cleaned up code for better readability and maintainability.

imagecatalog/Controls/PathPickerField.axaml

@@ -0,0 +1,34 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:iconPacks="https://github.com/MahApps/IconPacks.Avalonia"
+             x:Class="ImageCatalog_2.Controls.PathPickerField"
+             x:Name="Root">
+    <Grid ColumnDefinitions="Auto,*,Auto,Auto" ColumnSpacing="6">
+        <TextBlock Grid.Column="0"
+                   Text="{Binding Label, ElementName=Root}"
+                   VerticalAlignment="Center"
+                   Margin="0,0,8,0" />
+        <TextBox Grid.Column="1"
+                 Text="{Binding Text, ElementName=Root, Mode=TwoWay}"
+                 IsReadOnly="{Binding IsTextReadOnly, ElementName=Root}"
+                 Watermark="{Binding Watermark, ElementName=Root}"
+                 VerticalAlignment="Center" />
+        <Button Grid.Column="2"
+                Width="104"
+                IsVisible="{Binding ShowPickerButton, ElementName=Root}"
+                Click="PickPath_Click">
+            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Spacing="6">
+                <iconPacks:PackIconMaterial Kind="FolderOpenOutline" Width="14" Height="14" />
+                <TextBlock Text="Scegli..." />
+            </StackPanel>
+        </Button>
+        <Button Grid.Column="3"
+                Width="72"
+                Click="OpenPath_Click">
+            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Spacing="6">
+                <iconPacks:PackIconMaterial Kind="Folder" Width="14" Height="14" />
+                <TextBlock Text="Apri" />
+            </StackPanel>
+        </Button>
+    </Grid>
+</UserControl>