Missing Seaweed-* headers for active-active replication and async backup

[lewisl9029]

Describe the bug
Both active-active replication and async backup seem to fail to replicate Seaweed-* headers. (not sure if related, happy to split out into separate issues if not)

System Setup
I've set up a repo with docker-compose and detailed steps to repro both of these issues:
https://github.com/lewisl9029/seaweed-async-replication-repro

Happy to provide details if anything is still unclear.

Expected behavior
Files replicated through active-active replication and async backup should include Seaweed-* headers.

Screenshots
See screenshots in https://github.com/lewisl9029/seaweed-async-replication-repro/blob/main/README.md

Additional context
Original discussion: #3529

[chrislusf]

Thanks for the detailed bug report! I added a fix. Please help to confirm.

[lewisl9029]

@chrislusf thank you so much for the fix! Was just able to confirm that the headers are showing up in async replication!

Though I just ran into a different issue for backup. A whole bunch of errors that look like this:

reflame-storage-primary  | backup  | E0915 00:24:00.211679 filer_pb_tail.go:79 process directory:"/resources" event_notification:{old_entry:{name:"4chiq_97qWIqjkE9FI656HUZZwHEDRBb96j0RRA06uU" chunks:{file_id:"1,0110a4dfdd50" size:15705 mtime:1663198121169588555 e_tag:"mWap5CpVrTPRSGTelR5DBw==" source_file_id:"5,0118375d8618" fid:{volume_id:1 file_key:272 cookie:2766134608} source_fid:{volume_id:5 file_key:280 cookie:928876056}} attributes:{file_size:15705 mtime:1663198121 file_mode:432 crtime:1663198121 mime:"application/json" md5:"\x99f\xa9\xe4*U\xad3\xd1Hdޕ\x1eC\x07"} extended:{key:"Seaweed-Meta" value:"{\"headers\":{\"cache-control\":\"public, max-age=31536000, immutable\",\"content-type\":\"application/json\"}}"}} new_entry:{name:"4chiq_97qWIqjkE9FI656HUZZwHEDRBb96j0RRA06uU" chunks:{file_id:"7,0209a4947b05" size:15705 mtime:1663200833339500005 e_tag:"mWap5CpVrTPRSGTelR5DBw==" fid:{volume_id:7 file_key:521 cookie:2761194245}} attributes:{file_size:15705 mtime:1663200833 file_mode:432 crtime:1663198121 mime:"application/json" md5:"\x99f\xa9\xe4*U\xad3\xd1Hdޕ\x1eC\x07"} extended:{key:"Seaweed-Meta" value:"{\"headers\":{\"cache-control\":\"public, max-age=31536000, immutable\",\"content-type\":\"application/json\"}}"}} delete_chunks:true new_parent_path:"/resources" signatures:1384205955} ts_ns:1663200833345144630: InvalidArgument: The header 'x-amz-tagging' shall be encoded as UTF-8 then URLEncoded URL query parameters without tag name duplicates.
reflame-storage-primary  | backup  |    status code: 400, request id: PWZ95KK5PPDP93V1, host id: LkxVG2FYizeCyxrgChJB1gZb1dgTiyDOD8c2MYok8h0rZxtbRBoABv1wXqSUYicwjN9lzfNn2BU=

Relevant part seems to be this message near the end: InvalidArgument: The header 'x-amz-tagging' shall be encoded as UTF-8 then URLEncoded URL query parameters without tag name duplicates.

Maybe we're missing a URL encoding step somewhere?