Add makefile target 'show_build_options' and 'show_all_features' (#5048)

* Add makefile target 'show_build_options' and 'show_all_features'

Example:
```
$ make  planck:default:show_all_features
QMK Firmware 0.6.266
Making planck/rev5 with keymap default and target show_all_features

 PLATFORM = AVR
 FIRMWARE_FORMAT = hex

Build Options:
  BOOTMAGIC_ENABLE = no
  MOUSEKEY_ENABLE = no
  EXTRAKEY_ENABLE = yes
  CONSOLE_ENABLE = yes
  COMMAND_ENABLE = no
  SLEEP_LED_ENABLE = no
  NKRO_ENABLE = yes
  BACKLIGHT_ENABLE = no
  RGBLIGHT_ENABLE = no
  MIDI_ENABLE = no
  UNICODE_ENABLE = no
  BLUETOOTH_ENABLE = no
  AUDIO_ENABLE = yes
  FAUXCLICKY_ENABLE =
  HD44780_ENABLE =

Other Features:
  API_SYSEX_ENABLE = no
  RGB_MATRIX_ENABLE = no
```

* remove duplicate 'SPLIT_KEYBOARD'

* add .PHONY, change 'echo' -> '@echo'

* update show_options.mk: useing variable BUILD_OPTION_NAMES, HARDWARE_OPTION_NAMES and OTHER_OPTION_NAMES

* update show_options.mk: add KEYBOARD,KEYMAP

* update show_options.mk: add sorting

* update show_options.mk: add show_full_features, add $(origin XXX)

* update show_options.mk: Macro names was collected from keyboards/.

* update show_options.mk: add some Macro Names

0 files changed, 0 insertions, 0 deletions