Fix CORs support in dataAPI

[pschork]

This change adds OPTIONS request support to DataAPI gin router to allow CORS requests.

DataAPI was not setup to respond to HTTP:OPTIONS request which is used by browser to determine CORS options before it actually attempts the CORS request. Effectively dataAPI CORS support was broken and any CORS request was rejected.

Configure allowed CORS origin

DATA_ACCESS_API_ALLOW_ORIGINS=https://allowed-origin.xyz
DATA_ACCESS_API_SERVER_MODE=release

Verify HTTP:OPTIONS request succeeds for origin https://allowed-origin.xyz

curl -v -X OPTIONS "http://localhost:8080/api/v2/blobs/feed?limit=10" -H "Origin: https://allowed-origin.xyz"
* Host localhost:8080 was resolved.
* IPv6: ::1
* IPv4: 127.0.0.1
*   Trying [::1]:8080...
* Connected to localhost (::1) port 8080
> OPTIONS /api/v2/blobs/feed?limit=10 HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/8.6.0
> Accept: */*
> Origin: https://allowed-origin.xyz
>
< HTTP/1.1 204 No Content
< Access-Control-Allow-Credentials: true
< Access-Control-Allow-Headers: Origin,Content-Type,Accept,Authorization
< Access-Control-Allow-Methods: GET,POST,HEAD,OPTIONS
< Access-Control-Allow-Origin: https://allowed-origin.xyz
< Access-Control-Max-Age: 43200
< Vary: Origin
< Vary: Access-Control-Request-Method
< Vary: Access-Control-Request-Headers
< Date: Wed, 29 Jan 2025 03:59:01 GMT

Verify HTTP:OPTIONS request BLOCKED for origin https://foobar.com:1234

curl -v -X OPTIONS "http://localhost:8080/api/v2/blobs/feed?limit=10" -H "Origin: http://foobar.com:1234"
* Host localhost:8080 was resolved.
* IPv6: ::1
* IPv4: 127.0.0.1
*   Trying [::1]:8080...
* Connected to localhost (::1) port 8080
> OPTIONS /api/v2/blobs/feed?limit=10 HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/8.6.0
> Accept: */*
> Origin: http://foobar.com:1234
>
< HTTP/1.1 403 Forbidden
< Date: Wed, 29 Jan 2025 03:58:54 GMT
< Content-Length: 0

[jianoaix]

The order to set this up matters?

[pschork]

See :233 CORS middleware needs to be created before routes.