Implement HQQ quantization

[EricLBuehler]

This adds support for HQQ quantization in 8, 4, 3, 2, and 1 bit.

Still need to add:

• CPU dequant with simd accel, Metal dequant
• Quantization optimizer

[github-actions]

Code Metrics Report

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 Language            Files        Lines         Code     Comments       Blanks
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 Dockerfile              1           34           25            0            9
 Happy                   1          442          369            0           73
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 Python                 45         1993         1695           62          236
 TOML                   20          606          535           11           60
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 Jupyter Notebooks       4            0            0            0            0
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 (Total)                            273          201           32           40
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 Markdown               27         1894            0         1427          467
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 |- JSON                 1           12           12            0            0
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 (Total)                           2582          620         1446          516
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 Rust                  184        57550        52275         1007         4268
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 (Total)                          58423        52288         1817         4318
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 Total                 296        62656        55028         2507         5121
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