Add QDepthwiseConv2D, DepthwiseConv2D, DepthwiseConv1D support

[jmitrevs]

Description

There was a request to add support for QDepthwiseConv2D for QKeras. Previously we had Keras support for DepthwiseConv1D and DepthwiseConv2D but only as part of separable convolutions. This PR adds support for standalone DepthwiseConv1D and DepthwiseConv2D, and also QDepthwiseConv2D. Currently only depth_multiplier=1 is supported.

Note that QKeras doesn't support QDepthwiseConv1D.

Adding this found an issue in that arguments to activations passed as parameters to, e.g. QDense, such as activation='quantized_relu(3, 0)', were ignored. This had the same effect as activation='quantized_relu()'.

Type of change

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

Tests

Tests added to both test_keras_api.py and test_qkeras.py

Checklist

• [x] I have read the guidelines for contributing.
• [x] I have commented my code, particularly in hard-to-understand areas.
• [x] I have made corresponding changes to the documentation.
• [x] My changes generate no new warnings.
• [x] I have installed and run pre-commit on the files I edited or added.
• [x] I have added tests that prove my fix is effective or that my feature works.

[jmitrevs]

I should also mention that this is only for 'io_stream` and only for Vivado and Vitis. There is not Quartus support.

[jmitrevs]

I think we should also support depth_multiplier!=1. Or is that not used often?

[jmitrevs]

@bo3z, are there any other things needed for this PR?

[bo3z]

@bo3z, are there any other things needed for this PR?

Looks good to me. Maybe worth opening an issue to keep track of the TODOs from this PR (resource strategy and multiplier != 1).