Change visibility of handler classes to protected

[PillFall]

Some properties and methods of the handler classes are set to private and some others to protected.

I change the visibility of all of them to protected. I believe this is a better practice, as it allows us to extend the handler.

If there are any security concerns of why this is the way it is, please do let me know.

Example

The MongoDBHandler stores the configuration private as shown:

monolog/src/Monolog/Handler/MongoDBHandler.php

Lines 37 to 41 in d97d5e9

	private \MongoDB\Collection $collection;
	private Client|Manager $manager;
	private string|null $namespace = null;

But the DynamoDBHandler stores the configuration protected as shown:

monolog/src/Monolog/Handler/DynamoDbHandler.php

Lines 32 to 36 in d97d5e9

	protected DynamoDbClient $client;
	protected string $table;
	protected Marshaler $marshaler;

With how is the code right now, I can extend the DynamoDbHandler to add querying functionality, all without having to create a new configuration object (aka Aws\DynamoDb\DynamoDbClient).

But with MongoDBHandler, I have to redo the argument parsing in its construct function to include this functionality, creating also two copies of the same exact object in memory (aka MongoDB\Driver\Manager or \MongoDB\Collection).