Fixes #27840

Issue #27840

Issue #27840

With PHPUnit 8.5, which supports PHP >= 7.2, we no longer need the
temporary changes from issue #29882 to provide PHP 8.1 compatibility.

This reverts commit f82c03b by removing
the dependencies on custom forks of PHPUnit and required libraries.

Fixes #32810

  - Removing phpdocumentor/reflection-common (1.0.1)
  - Removing phpdocumentor/reflection-docblock (4.3.4)
  - Removing phpdocumentor/type-resolver (0.5.1)
  - Removing phpspec/prophecy (v1.10.3)
  - Removing phpunit/phpunit-mock-objects (5.0.10)
  - Removing symfony/polyfill-ctype (v1.19.0)
  - Removing webmozart/assert (1.9.1)
  - Upgrading doctrine/instantiator (1.0.5 => 1.5.0)
  - Upgrading myclabs/deep-copy (1.7.0 => 1.11.1)
  - Upgrading phar-io/manifest (1.0.1 => 2.0.3)
  - Upgrading phar-io/version (1.0.1 => 3.2.1)
  - Upgrading phpunit/php-code-coverage (dev-mantis-5.3 7642884 => 7.0.15)
  - Upgrading phpunit/php-file-iterator (dev-mantis-1.4 89be108 => 2.0.5)
  - Upgrading phpunit/php-timer (1.0.9 => 2.1.3)
  - Upgrading phpunit/php-token-stream (2.0.2 => 3.1.3)
  - Upgrading phpunit/phpunit (dev-mantis-6.5 215feef => 8.5.33)
  - Upgrading sebastian/comparator (2.1.3 => 3.0.5)
  - Upgrading sebastian/diff (2.0.1 => 3.0.4)
  - Upgrading sebastian/environment (3.1.0 => 4.2.4)
  - Upgrading sebastian/exporter (3.1.4 => 3.1.5)
  - Upgrading sebastian/global-state (2.0.0 => 3.0.3)
  - Upgrading sebastian/resource-operations (1.0.0 => 2.0.2)
  - Locking sebastian/type (1.1.4)
  - Upgrading theseer/tokenizer (1.1.3 => 1.2.1)

Replace with assertThat() and isType() constraint.

Replace with $this->expectException()

Replace with assertStringContainsString()

Replace with expectExceptionMessageMatches()

Prevents PHPUnit from throwing a warning:
No tests found in class "RestBase".

Fixes #32807

  - Removing symfony/polyfill-php72 (v1.19.0)
  - Removing symfony/polyfill-php70 (v1.19.0)
  - Removing symfony/polyfill-intl-normalizer (v1.19.0)
  - Removing symfony/polyfill-intl-idn (v1.19.0)
  - Removing paragonie/random_compat (v9.99.100)
  - Installing symfony/deprecation-contracts (v2.5.2)
  - Installing psr/http-client (1.0.2)
  - Upgrading guzzlehttp/guzzle (6.5.8 => 7.6.1)

Fixes #32807

Initialize defaultSoapClientOptions property in setUp(), to avoid a
syntax error due to undefined constant WSDL_CACHE_NONE.

Remove useless SoapAllTests::setUp() method. TestSuite class does not
have this method so it is never actually called. Extension availability
check is performed by `@requires extension` hints in the test cases'
PHPDoc blocks.

Fixes #32814

Argument #1 of PHPUnit\Framework\TestSuite::addTestSuite() must be a
class name or object

AllTests::suite() method called addTest() instead of addTestSuite()
to include the 3 tests suites.

Fixes #32815

Until today, the test suites were defined in "AllTests.php" files using
the PHPUnit\Framework\TestSuite class, which is meant for internal use.

The official, documented method to compose a test suite is to use XML
configuration.

This commit introduces the phpunit.xml, which replaces the AllTests.php
scripts, and updates documentation and TravisCI script.

Fixes #32816

When building test email addresses, use the user and domain from the
TEST_EMAIL constant, to ensure the test cases in providerEmailUnique
remain relevant in case the reference email is modified.

This avoids 'sh: 1: /usr/sbin/sendmail: not found' error message
displayed after PHPUnit suite execution, as sendmail is not installed on
Travis.

Note: This is not a "real" error and does not actually cause the build
to fail, but it could lead someone reviewing the build's log to think
that something went wrong, so it should be fixed to avoid confusion.

The fakesendmail.sh script was copied from PHPMailer's test suite [1].
It will generate a .eml file in /tmp/fakemail directory, each time
the test suite sends an email.

Fixes #32828

[1]: https://github.com/PHPMailer/PHPMailer/blob/v6.8.0/test/fakesendmail.sh