[image][online_image][animation] Fix transparency in RGB565 (#7631)

tests/components/image/common.yaml

@@ -0,0 +1,38 @@
+image:
+  - id: binary_image
+    file: ../../pnglogo.png
+    type: BINARY
+    dither: FloydSteinberg
+  - id: transparent_transparent_image
+    file: ../../pnglogo.png
+    type: TRANSPARENT_BINARY
+  - id: rgba_image
+    file: ../../pnglogo.png
+    type: RGBA
+    resize: 50x50
+  - id: rgb24_image
+    file: ../../pnglogo.png
+    type: RGB24
+    use_transparency: yes
+  - id: rgb565_image
+    file: ../../pnglogo.png
+    type: RGB565
+    use_transparency: no
+  - id: web_svg_image
+    file: https://raw.githubusercontent.com/esphome/esphome-docs/a62d7ab193c1a464ed791670170c7d518189109b/images/logo.svg
+    resize: 256x48
+    type: TRANSPARENT_BINARY
+  - id: web_tiff_image
+    file: https://upload.wikimedia.org/wikipedia/commons/b/b6/SIPI_Jelly_Beans_4.1.07.tiff
+    type: RGB24
+    resize: 48x48
+  - id: web_redirect_image
+    file: https://avatars.githubusercontent.com/u/3060199?s=48&v=4
+    type: RGB24
+    resize: 48x48
+  - id: mdi_alert
+    file: mdi:alert-circle-outline
+    resize: 50x50
+  - id: another_alert_icon
+    file: mdi:alert-outline
+    type: BINARY