Pooling Template Fix and HGQ2 QPooling Layer Support

[calad0i]

Description

(This PR includes #1321)

• Fixes pooling layers in io parallel implementation when strides are non-trivial (!= pool_size)
• Fixes keras v3 parser padding computation
• Added QPooling layer support for HGQ2

Known Issue

• Pooling in io_stream with non-trivial strides could still crash, most likely when strides > pool_size.

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change which adds functionality)

Tests

Updated test_pooling.py; HGQ2 tests are added in the HGQ2 repo.
(keras v3 tests will not be triggered here anyway; in the future maybe we can directly reuse HGQ2's hls4ml convert tests)

Test Configuration:

Checklist

• all, but no doc