Connection::open() should have SensitiveParameter

Problem/Motivation

It seems this was discussed in #3296293: Apply SensitiveParameter attribute but never done.

If open() triggers an exception or an error, the credentials can be visible in the stack trace.
It seems by default Drupal does not show the content of arrays in stack traces:

Drupal\mysql\Driver\Database\mysql\Connection::open(Array) (Line: 50)
test_preprocess_page(Array, 'page', Array) (Line: 354)

But it can happen when using other tools to display the stack trace (for example the Symfony Error Handler):

ErrorException:
Warning: Array to string conversion

  at core/modules/mysql/src/Driver/Database/mysql/Connection.php:110
  at Drupal\mysql\Driver\Database\mysql\Connection::open(array('password' => 'foo', 'host' => array()))
     (modules/custom/test/test.module:50)

Steps to reproduce

  ini_set('zend.exception_ignore_args', FALSE);
  $options = ['password' => 'foo', 'host' => []];
  Connection::open($options);

Proposed resolution

Add #[SensitiveParameter] to the $connection_options argument.

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet