Ensure email param is properly encoded in delete_connection_user [SDK-2660]

[Widcket]

Changes

This PR modifies the delete_connection_user method, putting the email query param inside the body hash parameter of the delete method, so it gets properly encoded and added as a query param to the URL by the rest-client gem.

Previously, this query param was added directly to the endpoint path, which resulted in it not being properly percent-encoded (the reserved characters as per RFC 3986 were not encoded). This resulted in the endpoint returning an error due to the input validation failed with emails like [email protected], because + was not percent-encoded.

See similar instance: https://github.com/auth0/ruby-auth0/blob/master/lib/auth0/api/v2/user_blocks.rb#L30

Why the query param needs to be added to body

See https://github.com/auth0/ruby-auth0/blob/master/lib/auth0/mixins/httpproxy.rb.

This is the body parameter of the delete method:

When the HTTP method is :delete, that method calls the call method to make the HTTP request with rest-client.

Due to the peculiar API rest-client offers to pass parameters when using arbitrary HTTP methods, the parameters (the body hash in the case of :delete) must to be added to the headers hash:

The call method then invokes rest-client with that headers hash containing the query params, that are then properly encoded and added to the URL:

Testing

This change has been tested on ruby 2.7.1p83.

• This change adds unit test coverage
• This change adds integration test coverage
• This change has been tested on the latest version of Ruby

Checklist

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 Code of Conduct
• All existing and new tests complete without errors
• Rubocop passes on all added/modified files
• All active GitHub checks have passed