Add wgpu::TextureFormat::RGB9E5Ufloat

Also update RG11B10Float to be name RG11B10Ufloat

Bug: dawn:22

Change-Id: I0ea76dc25c37ebaeb4c2c2c2a119d00940acc145
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/25760
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Stephen White <senorblanco@chromium.org>
Commit-Queue: Kai Ninomiya <kainino@chromium.org>

generator/templates/webgpu_cpp.h

@@ -26,6 +26,10 @@ namespace wgpu {
             {% for value in type.values %}
                 {{as_cppEnum(value.name)}} = 0x{{format(value.value, "08X")}},
             {% endfor %}
+            //* TODO(dawn:22) remove this once the PSA is sent and the deadline passed.
+            {% if type.name.canonical_case() == "texture format" %}
+                RG11B10Float = RG11B10Ufloat,
+            {% endif %}
         };
 
     {% endfor %}