Fix "Misordered 'assertEquals()', 'assertSame()' arguments"

Problem/Motivation

1) In some tests in function assertEquals(), assertSame() arguments type is miss ordered.

public function assertEquals($expected, $actual, $delta = 0.0, $canonicalize = FALSE, $ignoreCase = FALSE)
public static function assertSame($expected, $actual, string $message = '')

2) In some places assertCount() is better fit.

$this->assertEquals(1, count($mails));

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes