Add ability to use Q5_0, Q5_1, and IQ4_NL for quantized K cache (#6183)

Add ability to use Q5_0, Q5_1, and IQ4_NL for quantized K cache (#6183)

* k_cache: be able to use Q5_0

* k_cache: be able to use Q5_1 on CODA

* k_cache: be able to use Q5_0 on Metal

* k_cache: be able to use Q5_1 on Metal

* k_cache: be able to use IQ4_NL - just CUDA for now

* k_cache: be able to use IQ4_NL on Metal

* k_cache: add newly added supported types to llama-bench and CUDA supports_op

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Co-authored-by: Iwan Kawrakow <redacted>