Optimize template images + disable image optim docker (#313)

* Optimize template images + disable image optim docker

* Fix new name default docker env variable name

* Re-establish template page cache

client/lib/images/dummy-image-provider.js

@@ -0,0 +1,21 @@
+import { joinURL } from 'ufo'
+import { createOperationsGenerator } from '#image'
+
+const operationsGenerator = createOperationsGenerator()
+
+export const getImage = (
+  src,
+  { modifiers = {}, baseURL } = {}
+) => {
+
+  if (!baseURL) {
+    // also support runtime config
+    baseURL = useRuntimeConfig().public.siteUrl
+  }
+
+  const operations = operationsGenerator(modifiers)
+
+  return {
+    url: joinURL(baseURL, src + (operations ? '?' + operations : '')),
+  }
+}