tests: Add visual/edittext/edittext_caret_empty

This test verifies how the caret in a text field is rendered when
the text field is empty.

tests/tests/swfs/visual/edittext/edittext_caret_empty/input.json

@@ -0,0 +1,26 @@
+[
+  { "type": "KeyDown", "key_code": 9 },
+  { "type": "Wait" },
+  { "type": "KeyDown", "key_code": 9 },
+  { "type": "Wait" },
+  { "type": "KeyDown", "key_code": 9 },
+  { "type": "Wait" },
+  { "type": "KeyDown", "key_code": 9 },
+  { "type": "Wait" },
+  { "type": "KeyDown", "key_code": 9 },
+  { "type": "Wait" },
+  { "type": "KeyDown", "key_code": 9 },
+  { "type": "Wait" },
+  { "type": "KeyDown", "key_code": 9 },
+  { "type": "Wait" },
+  { "type": "KeyDown", "key_code": 9 },
+  { "type": "Wait" },
+  { "type": "KeyDown", "key_code": 9 },
+  { "type": "Wait" },
+  { "type": "KeyDown", "key_code": 9 },
+  { "type": "Wait" },
+  { "type": "KeyDown", "key_code": 9 },
+  { "type": "Wait" },
+  { "type": "KeyDown", "key_code": 9 },
+  { "type": "Wait" }
+]

tests/tests/swfs/visual/edittext/edittext_caret_empty/test.toml

@@ -0,0 +1,52 @@
+num_ticks = 12
+
+[image_comparisons."output.01"]
+trigger = 1
+tolerance = 128
+
+[image_comparisons."output.02"]
+trigger = 2
+tolerance = 128
+
+[image_comparisons."output.03"]
+trigger = 3
+tolerance = 128
+
+[image_comparisons."output.04"]
+trigger = 4
+tolerance = 128
+
+[image_comparisons."output.05"]
+trigger = 5
+tolerance = 128
+
+[image_comparisons."output.06"]
+trigger = 6
+tolerance = 128
+
+[image_comparisons."output.07"]
+trigger = 7
+tolerance = 128
+
+[image_comparisons."output.08"]
+trigger = 8
+tolerance = 128
+
+[image_comparisons."output.09"]
+trigger = 9
+tolerance = 128
+
+[image_comparisons."output.10"]
+trigger = 10
+tolerance = 128
+
+[image_comparisons."output.11"]
+trigger = 11
+tolerance = 128
+
+[image_comparisons."output.12"]
+trigger = 12
+tolerance = 128
+
+[player_options]
+with_renderer = { optional = false, sample_count = 4 }