* dipsw test on helix/rev2/sc/back:five_rows
* add peek_matrix() to matrix_common.c
* add DIP_SWITCH_MATRIX_GRID support to quantum/dip_switch.c
* update docs/feature_dip_switch.md about DIP_SWITCH_MATRIX_GRID
* Test end. remove test code. Revert "dipsw test on helix/rev2/sc/back:five_rows"
This reverts commit 6d4304c74557597c9fb4d324f79c3ae4793ae874.
* Move some common matrix code to a common location
* Refactor some 'custom_matrix_helper' logic to use custom matrix lite
* Fix build for kinesis/stapelberg - abuse of vpath was picking up matrix.c from core when custom matrix was enabled
* Add validation for CUSTOM_MATRIX