Similar to PHPC-2699, add typed readonly properties to all BSON classes. The goal is to remove the need to have the get_properties_hash functions, and instead tracking properties in the standard zend_object properties table.

Note that adding properties and initialising them directly on BSON deserialisation could have a memory impact. To avoid negative impact, we should:

• add benchmarks to be able to compare the impact of the changes
• consider creating property zvals lazily when a property is accessed for the first time.

The MongoDB\BSON\Document and MongoDB\BSON\PackedArray classes are excluded from this: the former implements a dynamic access pattern using read_property and read_dimension, the latter represents an array which does not have any properties.