Keymap introspection for Dip Switches

[zvecr]

Description

With the eventual aim to support configuration of dip switches over XAP, this first pass enables similar keymap functionality as encoder map.

keymap.c

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
    [0] = LAYOUT_ortho_1x1(KC_A),
    [1] = LAYOUT_ortho_1x1(KC_B),
};

const uint16_t PROGMEM dip_switch_map[NUM_DIP_SWITCHES][NUM_DIP_STATES] = {
    DIP_SWITCH_OFF_ON(DF(0), DF(1))
};

Notes

• No layer support
  • generally used to toggle global state
    • implementing layers would be somewhat pointless
    • could still use custom keycodes

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[tzarc]

LGTM.