chore: Allow text/plain content type descriptor for json formatted content body

[NagyZoltanPeter]

Description

@weboko requested that from browser no-coors mode we need to supprt text/plain content-body requests.

Changes

• For decoding content body we now allow text/plain content-type descriptor as well
• Refactored rest type encode/decode functions to remove tons of code duplication.

How to test

1. Setup a light client node.
2. Send normal rest requests (POST/PUT) with curl as text/plain
3. Should work as normal as with application/json content-type (notice no json format changed)

Issue

#2207

[github-actions]

You can find the image built from this PR at

quay.io/wakuorg/nwaku-pr:2209

Built from 5ff6902

[vpavlin]

Didn't have time to actually run it, but from visual sanity check perspective it looks great (thanks for the refactoring!)

[gabrielmer]

LGTM, thanks so much!

[NagyZoltanPeter]

As @weboko pointed out, I missed converting /relay apis to accept text/plain requests, it is done now with some simplifications

[weboko]

Amazing, now it works. I noticed some of improvements that can be done:

• browsers by default send Content-Type with encoding - text/plain;charset=UTF-8 and since it is made to accept only text/plain it would fail with 400, in we probably should check similarly to Express.js;
• as additional precaution can we set Access-Control-Allow-Origi to * or make it configurable by config flag;

[fryorcraken]

as additional precaution can we set Access-Control-Allow-Origin to * or make it configurable by config flag;

Do not set it to * as it makes it a security issue as now any website can try to access a local running nwaku node using default port and would be authorized to then manipulate the nwaku node because the CORS would not stop it.

The CORS origin should only be localhost/127.0.0.1. @weboko, how are you hitting your webserver? I assume it's running in docker now? are you using the docker container ip to access the webserver? that might the issue, need to use the port exposed on localhost.

[NagyZoltanPeter]

Added support for decoding content body when content-type header argument has more parameters above media type.

[weboko]

The CORS origin should only be localhost/127.0.0.1

Browser recognizes CORS based on Same origin policy which unfortunately takes port into account, so event if it is same domain but ports are different it violates same origin policy.

If REST is intended to be user only locally - it should be enough with MIME change in this PR.

[fryorcraken]

If REST is intended to be user only locally - it should be enough with MIME change in this PR.

Yes, REST should be user only locally.