fix: incorrect urlencode encoding for JSON scalar, argument preset init

[hgiasac]

• Fix incorrectly encoding Arbitrary JSON scalar for application/x-www-form-urlencoded content type.
• Fix argument preset initialization in server settings.
• Disable HTML escape when encoding JSON.
• Reroute HTTP 4xx response from the remote request to HTTP 422 so the detail can appear in the graphql error.
• Use JSON for the result type if the response is unknown.

[github-actions]

Package	Line Rate	Health
github.com/hasura/ndc-http/connector	50%	➖
github.com/hasura/ndc-http/connector/internal/argument	52%	➖
github.com/hasura/ndc-http/connector/internal	56%	➖
github.com/hasura/ndc-http/connector/internal/contenttype	58%	➖
github.com/hasura/ndc-http/connector/internal/security	60%	➖
github.com/hasura/ndc-http/ndc-http-schema/configuration	40%	❌
github.com/hasura/ndc-http/ndc-http-schema/openapi/internal	49%	➖
github.com/hasura/ndc-http/ndc-http-schema/openapi	40%	➖
github.com/hasura/ndc-http/ndc-http-schema/schema	30%	❌
github.com/hasura/ndc-http/ndc-http-schema/utils	43%	➖
Summary	48% (4109 / 8513)	➖

Minimum allowed line rate is 40%