Correctly handle decimal physicial type mapping

[Fokko]

Apache Iceberg version

None

Please describe the bug 🐞

According to the spec:

Here we map everything to a fixed byte array:

iceberg-python/pyiceberg/io/pyarrow.py

Lines 1864 to 1865 in a275ce5

	def visit_decimal(self, decimal_type: DecimalType) -> str:
	return "FIXED_LEN_BYTE_ARRAY"

Let's add a test here with precision 8, 16 and 24:

iceberg-python/tests/io/test_pyarrow_stats.py

Line 449 in a275ce5

],

Willingness to contribute

• I can contribute a fix for this bug independently
• I would be willing to contribute a fix for this bug with guidance from the Iceberg community
• I cannot contribute a fix for this bug at this time

[redpheonixx]

Hi @Fokko
can I take this up? Thanks!

[Fokko]

@redpheonixx sure thing! Go for it