resolveMediaDump(ctx: Context,dumpId: string): Promise<{ dump: Dump; cacheControl: string; }>
Returns dump dumpId as the viewer of ctx's ?token= may see it, and the
Cache-Control its media get: kept for good under a URL naming the file's
current version (?v=, as dumpFileVersion gives), revalidated under any
other, and never in a shared cache for a private dump. It also keeps the
token out of the Referer of whatever the response links to.
Promise<{ dump: Dump; cacheControl: string; }>