Add TYPE_BIT constant to AdapterInterface

[dereuromark]

Summary

• Adds TYPE_BIT constant to AdapterInterface mapping to TableSchemaInterface::TYPE_BIT
• Bumps cakephp/database constraint to ^5.3.2 to require the version with BIT type support
• Complements the core BIT type support added in Add BIT type support to MysqlSchemaDialect cakephp#19223

Usage

After this change, users can define BIT columns in migrations:

$table->addColumn('flags', 'bit', ['limit' => 8]);
// or using the constant
$table->addColumn('flags', AdapterInterface::TYPE_BIT, ['limit' => 8]);