bug: store v3 returns error "illegal base64 data at input byte" for some cursors/hashes

[fbarbu15]

Describe the bug
Some cursors/hashes are returning this error, while some are working fine. It looks like a 50% of the cursors are affected
Very similar to nwaku bug logos-messaging/logos-delivery#2715

To reproduce

If you can reproduce the behavior, steps to reproduce:

1. Have 4 messages in the store
2. Send a store v3 request with page size 2. Ex response:
   {"requestId":"","statusCode":200,"statusDesc":"OK","messages":[{"messageHash":"lhxaAF/mQbvGj+WkU7SrqVg4xp9pErO+W8STZOoSOC8="},{"messageHash":"wMpdcbqPXkl+vBnh7H4Mdc48bjn7B0d7TLHycSgKSbw="}],"paginationCursor":"wMpdcbqPXkl+vBnh7H4Mdc48bjn7B0d7TLHycSgKSbw="}
3. Retrieve the paginationCursor from the response and use it in a new request. Ex request:
   curl -v -X GET "http://127.0.0.1:48732/store/v3/messages?pubsubTopic=%2Fwaku%2F2%2Frs%2F0%2F0&contentTopics=%2Fmyapp%2F1%2Flatest%2Fproto&cursor=wMpdcbqPXkl%2BvBnh7H4Mdc48bjn7B0d7TLHycSgKSbw%3D&pageSize=100&ascending=true" -H "Content-Type: application/json"

Actual behavior

400 Bad Request with illegal base64 data at input byte 11

Expected behavior

Should work

go-waku version/commit hash

harbor.status.im/wakuorg/go-waku:latest

Additional context
Same thing happens for the hashes key instead of cursor

Logs
publishing_node1.log
store_node1.log