Remove/Deprecate DkanSqlEndpointSettingsForm

[paul-m]

Current Behavior

The form class Drupal\datastore\SqlEndpoint\Form\DkanSqlEndpointSettingsForm has this docblock:

/**
 * Settings form for the SQL endpoint.
 *
 * NO LONGER USED; TO BE REMOVED.
 *
 * @package Drupal\sql_endpoint\Form
 * @todo Remove
 */
class DkanSqlEndpointSettingsForm extends ConfigFormBase {

This is related to PR #3693

Expected Behavior

Investigate whether this class is needed, or needs a more formalized @deprecated type deprecation.

Remove this class as needed.

Steps To Reproduce

• Notes regarding this deprecation/removal are added to this issue.
• Automated tests pass.

Relevant log output (optional)

No response

Anything else?

No response