Generalizes the esp_camera.h lesson into a table (esp_lcd_st77916,
esp_lcd_touch_cst816s, esp_lcd_gc9a01, esp_lcd_ek79007, esp32-camera)
and applies it in the arduino branch, the no-core pure-IDF fallback AND
the explicit language=espidf branch (issue #139) - the last one is where
the VoCat display example lives and previously died at the first
include. Validated on staging: the ST77916 colour-bars espidf example
now fetches espressif/esp_lcd_st77916 from the registry and compiles.
f606da2cbe