adds RenameAsync for tags

src/Piwigo.Client.Tests/TagApiTests.cs

@@ -93,4 +93,17 @@ public class TagApiTests : ApiTestsBase
 
         await Verify(response);
     }
+
+    [Test]
+    public async Task RenameAsync_should_pass_correct_parameters()
+    {
+        SetJsonResult(@"{""stat"":""ok"",""result"":{""id"":1,""name"":""tag1new"",""url_name"":""tag1new""}}");
+
+        await _tagApi.RenameAsync(1, "tag1new", ApiToken);
+
+        CorrectMethodShouldGetCalled("pwg.tags.rename");
+        CorrectParamShouldGetSent("tag_id", "1");
+        CorrectParamShouldGetSent("new_name", "tag1new");
+        CorrectParamShouldGetSent("pwg_token", ApiToken);
+    }
 }

src/Piwigo.Client/Tags/ITagApi.cs

@@ -63,6 +63,18 @@ public interface ITagApi
     /// <param name="cancellationToken">
     ///     <see cref="CancellationToken" />
     /// </param>
-    /// <returns></returns>
+    /// <returns>Information about the merge result</returns>
     Task<MergeResult> MergeAsync(int targetTagId, int sourceTagId, string apiToken, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    ///     renames a existing tag
+    /// </summary>
+    /// <param name="tagId">the tag id that gets renamed</param>
+    /// <param name="newName">the new name of the existing tag</param>
+    /// <param name="apiToken">The API token that can be read from <see cref="Piwigo.Client.Session.SessionStatus" /></param>
+    /// <param name="cancellationToken">
+    ///     <see cref="CancellationToken" />
+    /// </param>
+    /// <returns></returns>
+    Task RenameAsync(int tagId, string newName, string apiToken, CancellationToken cancellationToken = default);
 }

src/Piwigo.Client/Tags/TagApi.cs

@@ -76,4 +76,16 @@ public class TagApi : ITagApi
 
         return response.Result;
     }
+
+    public async Task RenameAsync(int tagId, string newName, string apiToken, CancellationToken cancellationToken = default)
+    {
+        var formParams = new Dictionary<string, string>
+        {
+            { "tag_id", tagId.ToString() },
+            { "new_name", newName },
+            { "pwg_token", apiToken }
+        };
+
+        await _context.PostAsync<PiwigoResponse>(_logger, "pwg.tags.rename", formParams, cancellationToken);
+    }
 }