imatrix: add option to display importance score statistics for a given imatrix file...

imatrix: add option to display importance score statistics for a given imatrix file (#12718)

* Add --show-statistics option

* Add --show-statistics logic

* Add tensor name parsing

* Tidy output format

* Fix typo in title

* Improve tensor influence ranking

* Add better statistics

* Change statistics' sort order

* Add Cosine Similarity

* Add header search path

* Change header search path to private

* Add weighted statistics per layer

* Update report title

* Refactor compute_statistics out of main

* Refactor compute_cossim out of load_imatrix

* Refactor compute_statistics out of load_imatrix

* Move imatrix statistics calculation into its own functions

* Add checks and validations

* Remove unnecessary include directory

* Rename labels

* Add m_stats getter and refactor compute_statistics out of load_imatrix

* Refactor variable names

* Minor cosmetic change

* Retrigger checks (empty commit)

* Rerun checks (empty commit)

* Fix unnecessary type promotion

Co-authored-by: compilade <redacted>
* Reverting change to improve code readability

* Rerun checks (empty commit)

* Rerun checks (empty commit)

* Rerun checks - third time's the Charm 🤞 (empty commit)

* Minor cosmetic change

* Update README

* Fix typo

* Update README

* Rerun checks (empty commit)

* Re-implement changes on top of #9400

* Update README.md

* Update README

* Update README.md

Co-authored-by: compilade <redacted>
* Update README.md

Co-authored-by: compilade <redacted>
* Update README.md

* Remove duplicate option in print_usage()

* Update README.md

* Update README.md

Co-authored-by: compilade <redacted>
* Update README.md

Co-authored-by: compilade <redacted>
* Remove input check

* Remove commented out code

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Co-authored-by: compilade <redacted>