Make `or` expression JSON serializable

[Fokko]

Feature Request / Improvement

Make sure that the or expression can be serialized to JSON:

iceberg-python/pyiceberg/expressions/__init__.py

Line 293 in e5e7453

class Or(BooleanExpression):

This should follow:

{
    "type": "or",
    "left": BooleanExpression,
    "right": BooleanExpression
}

Where BooleanExpression refers to the class:

iceberg-python/pyiceberg/expressions/__init__.py

Line 250 in e5e7453

class And(BooleanExpression):

We use Pydantic for JSON serialization, which can be enabled by deriving from the IcebergBaseModel:

iceberg-python/pyiceberg/partitioning.py

Line 124 in e5e7453

class PartitionSpec(IcebergBaseModel):

Example tests can be found here:

iceberg-python/tests/table/test_partitioning.py

Lines 116 to 132 in e5e7453

	def test_serialize_partition_spec() -> None:
	partitioned = PartitionSpec(
	PartitionField(source_id=1, field_id=1000, transform=TruncateTransform(width=19), name="str_truncate"),
	PartitionField(source_id=2, field_id=1001, transform=BucketTransform(num_buckets=25), name="int_bucket"),
	spec_id=3,
	)
	assert (
	partitioned.model_dump_json()
	== """{"spec-id":3,"fields":[{"source-id":1,"field-id":1000,"transform":"truncate[19]","name":"str_truncate"},{"source-id":2,"field-id":1001,"transform":"bucket[25]","name":"int_bucket"}]}"""
	)
	def test_deserialize_unpartition_spec() -> None:
	json_partition_spec = """{"spec-id":0,"fields":[]}"""
	spec = PartitionSpec.model_validate_json(json_partition_spec)
	assert spec == PartitionSpec(spec_id=0)

[tanmayrauth]

Hi @Fokko, can work on this issue?

[Fokko]

I've removed the label and this one is up for grabs. Keep in min that this issue requires BooleanExpression to extend IcebergBaseModel, so it would be good to get the unary/literal/set predicates in first.

[tanmayrauth]

Can I work on this one now?