Adding gif support (#1225)

* Adding gif to accepted image extension and unit test

* Revert "Adding gif to accepted image extension and unit test"

This reverts commit d0df823906.

* Adding gif support and unit test

* unit test and event widget

- updating unit test archives to temive unneeded gifs, causing failures
- adding overflow to event widget

API.Tests/Parser/ParserTest.cs

@@ -179,6 +179,7 @@ namespace API.Tests.Parser
         [InlineData(".test.jpg", false)]
         [InlineData("!test.jpg", true)]
         [InlineData("test.webp", true)]
+        [InlineData("test.gif", true)]
         public void IsImageTest(string filename, bool expected)
         {
             Assert.Equal(expected, IsImage(filename));