fix(route): handle /api/v0/name/resolve/arg

[ns4plabs]

No description provided.

[hacdias]

Hmmm, Kubo does not support the trailing slash. Did we ever support this in the public gateways?

curl -I -X POST "http://127.0.0.1:5001/api/v0/name/resolve?arg=ipfs.tech"
HTTP/1.1 200 OK

curl -I -X POST "http://127.0.0.1:5001/api/v0/name/resolve/?arg=ipfs.tech"
HTTP/1.1 500 Internal Server Error

[lidel]

I think both were technically allowed by https://github.com/ipfs/go-ipfs-cmds/ and Kubo:

$ curl "http://127.0.0.1:8080/api/v0/name/resolve/ipfs.tech"
{"Path":"/ipfs/Qmb3zPY1qxAB5Jha4jWVRqkPxAdnukJUtNAjC7GMfyTdhj"}

$ curl "http://127.0.0.1:8080/api/v0/name/resolve?arg=ipfs.tech"
{"Path":"/ipfs/Qmb3zPY1qxAB5Jha4jWVRqkPxAdnukJUtNAjC7GMfyTdhj"}

but can't use both notations at the same time:

$ curl "http://127.0.0.1:8080/api/v0/name/resolve/?arg=ipfs.tech"
{"Message":"invalid path \"/ipns/\": path does not have enough components","Code":0,"Type":"error"}

iirc trailing slash means arg is the terminus of the path, so you can't pass arg as arg and have trailing slash at the same time (fix below)