Marked connection exception test incomplete on MySQL 8

Fix Appveyor builds

Support for comments on table in all databases

Fix typo in docblock

Using command line options to configure MySQL 8 instead of mounting a config file

Fixed test failures on PHP 7.4

The failures are caused by the changes in PHP according to https://wiki.php.net/rfc/notice-for-non-valid-array-container.

Bumped PHPUnit requrement to ^8.3.3, removed dependency on symfony/phpunit-bridge

Switched from ibmcom/db2express-c to ibmcom/db2

Change "we're" to "where" in docblock for listTableColumns()
method. Add comma to improve readability.

Add commit result bool

Compare type class when comparing columns.

Added a unit test for Doctrine\DBAL\Logging\LoggerChain

Reworked the mocks generated by Prophecy using PHPUnit

Updated PHPUnit to 8.2.1

The new version contains some improvements in handling mocks (https://github.com/sebastianbergmann/phpunit/issues/3602) and will help identify some existing issues in DBAL 3.0 tests:

There were 2 warnings:

1) Doctrine\Tests\DBAL\Driver\OCI8\OCI8StatementTest::testExecute with data set #0 (array('test', null, 'value'))
Method bindValue may not return value of type boolean

2) Doctrine\Tests\DBAL\Driver\OCI8\OCI8StatementTest::testExecute with data set #1 (array(null, 'test', 'value'))
Method bindValue may not return value of type boolean

Updated Jetbrains PhpStorm stubs to 2019.1

Deprecated some unused code bits

Make LoggerChain use constructor to add loggers instead of adder method

Enforced parameter and return value types in test classes

Upgraded to PHPUnit 8.1.6 and reworked the remaining driver exception mock

Allow Symfony 5

add .github/FUNDING.yml