Move Range header implementation from cache to shared

We'll need this for R2 too

Author: mrbbot

packages/tre/src/plugins/cache/gateway.ts

@@ -7,8 +7,8 @@ import { Headers, HeadersInit, Request, Response, fetch } from "../../http";
 import { Clock, Log, millisToSeconds } from "../../shared";
 import { Storage } from "../../storage";
 import { isSitesRequest } from "../kv";
+import { _getRangeResponse } from "../shared";
 import { CacheMiss, PurgeFailure, StorageFailure } from "./errors";
-import { _getRangeResponse } from "./range";
 
 interface CacheMetadata {
   headers: string[][];

packages/tre/src/plugins/cache/index.ts

@@ -93,4 +93,3 @@ export const CACHE_PLUGIN: Plugin<
 };
 
 export * from "./gateway";
-export * from "./range";

packages/tre/src/plugins/shared/index.ts

@@ -64,5 +64,6 @@ export function namespaceEntries(
 
 export * from "./constants";
 export * from "./gateway";
+export * from "./range";
 export * from "./router";
 export * from "./routing";