Introduce properties for SQL parts in QueryBuilder

Added the missing argument type to Connection::executeQuery($types)

Fixed the QueryBuilder::setMaxResults() signature to accept NULL

Enforced argument and return types in QueryBuilder and ExpressionBuilder

The original signature was improperly documented which later became enforced.

Replaced func_get_args() with variadic arguments

Introduce From class in QueryBuilder

Fix phpstan error

Introduce Join class in QueryBuilder

Fix phpstan errors

Fix some whitelisted PHPStan errors

Removed Connection::project()

The methods has more limitations and caveats than provides real use:

1. It fetches all data in memory which is often inefficient (see #2718).
2. It fetches rows in memory one by one instead of using `fetchAll()`.
4. It doesn't allow to specify the statement fetch mode since it's instantiated internally.
5. It can be easily replaced with:
   ```php
   foreach ($conn->executeQuery($query, $params, $types) as $value) {
      yield $function($value);
   }
   ```

Fix phpstan errors

Removed the OCI8Connection::getExecuteMode() method

The existing relationship between the connection and its statement violate the ISP principle. Instead of having access only to the execution mode of the connection, statements have access to the entire connection API.

Having a method which is not defined in the driver connection interface makes it impossible to mark the method `final` (#3590).

Made the OCI8Statement class final

Refactored MySQLiStatement::$columnNames

The `$columnNames` property has a too complex type `string[]|false|null` which leads to:

1. Non-trivial to understand conditions and assertions like `if ($columnNames === false)`, `if ($columnNames === true)` and `assert(is_array($columnNames))`.
2. Avoidable [false-positives](https://scrutinizer-ci.com/g/doctrine/dbal/inspections/20d1aea4-2217-4f38-8adc-5ce10fa9cf0b/issues/files/lib/Doctrine/DBAL/Driver/Mysqli/MysqliStatement.php?status=new&orderField=path&order=asc&honorSelectedPaths=0) on Scrutinizer that thinks that `$columnNames` can be TRUE.

Make classes final where applicable.