feat: make store fetch messages by hash

[weboko]

Description

The Waku Store protocol specification supports querying messages by their hash, but our current implementation makes this impossible due to validation logic conflicts. When attempting to use messageHashes as a query parameter, users encounter a catch-22:

1. Using queryGenerator requires passing decoders, which automatically sets pubsubTopic and contentTopics
2. The validation logic then rejects the query with an error:

if (
  params.messageHashes &&
  params.messageHashes.length > 0 &&
  (params.pubsubTopic ||
    (params.contentTopics && params.contentTopics.length > 0) ||
    params.timeStart ||
    params.timeEnd)
) {
  throw new Error(
    "Message hash lookup queries cannot include content filter criteria"
  );
}

This makes it currently impossible to use the message hash lookup feature that's specified in the protocol, despite it being exposed in our API interfaces.

User Story

As a developer, I want to query specific messages by their hash directly, so that I can efficiently retrieve exactly the messages I need without having to filter through time-based or content-based results.

Proposed Solution / Feature Design

Fix the validation logic to properly handle message hash queries:

[weboko]

@adklempner to add description

also we need to add E2E interop tests for this usage of Store

[adklempner]

related to #2330