adapter(cloudflare): removed durable mode, added withPlatformProxy (#233)

* removed `durable` mode as it requires an import from "cloudflare:" that often fails in non-cf environments

* remove worker configuration types

* add `withPlatformProxy`

* withPlatformProxy: make configuration optional

examples/cloudflare-worker/bknd.config.ts

@@ -0,0 +1,12 @@
+/**
+ * Optionally wrapping the configuration with the `withPlatformProxy` function
+ * enables programmatic access to the bindings, e.g. for generating types.
+ */
+
+import { withPlatformProxy } from "bknd/adapter/cloudflare";
+
+export default withPlatformProxy({
+   d1: {
+      session: true,
+   },
+});