T-Echo screen and button performance (#3840)

* Make button timing configurable per variant

* Adjust button timing for T-Echo
Easier multi-clicks for features like "toggle backlight" (4x click)

* Fewer full-refreshes for T-Echo display
Disables ghost pixel tracking: T-Echo ghost pixels are fairly faint.

variants/t-echo/variant.h

@@ -65,6 +65,9 @@ extern "C" {
 #define PIN_BUTTON2 (0 + 18)      // 0.18 is labeled on the board as RESET but we configure it in the bootloader as a regular GPIO
 #define PIN_BUTTON_TOUCH (0 + 11) // 0.11 is the soft touch button on T-Echo
 
+#define BUTTON_CLICK_MS 400
+#define BUTTON_TOUCH_MS 200
+
 /*
  * Analog pins
  */