quantize : add --dry-run option (#19526)

quantize : add --dry-run option (#19526)

* clean slate for branch

* use 6 characters for tensor dims

* add --dry-run to llama-quantize

* use 6 characters for tensor dims (cont.)

* no need to re-calculate ggml_nbytes for tensor

* fix indent

* show model and quant BPW when quant completes

* add example to --help

* new function `tensor_requires_imatrix`, add courtesy warning about imatrix

* missing __func__, move imatrix flag set

* logic error

* fixup tensor_requires_imatrix

* add missing `GGML_TYPE`s

* simplify and rename `tensor_type_requires_imatrix`

* simplify for style

* add back Q2_K edge case for imatrix

* guard ftype imatrix warning

* comment ref #12557

* remove per @compilade

* remove unused `params` parameter

* move `bool dry_run` per GG

* move `bool dry_run` per GG

* Update src/llama-quant.cpp

Co-authored-by: Sigbjørn Skjæret <redacted>
* Update src/llama-quant.cpp

Co-authored-by: Sigbjørn Skjæret <redacted>
* Update src/llama-quant.cpp

Co-authored-by: Sigbjørn Skjæret <redacted>
---------

Co-authored-by: Sigbjørn Skjæret <redacted>