* 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.