WS2812 real-time Leds panel as Berry app

[s-hadinger]

Description:

Experimental feature

Adds an optional panel that mirrors on the WebUI the colors displayed on the Leds strip in real-time.

Example with a simple strip with 25 Leds with Pixels 25 and Scheme 12:

Example with a matrix 16x8 with Pixels 256,0,8,0 and Scheme 12:

It is enabled by clicking on "[Load Leds Panel]" in the "Tools" menu. This button is only available on ESP32/C3/S2/S3... only (no ESP8266), and when is GPIO WS2812 - 1 is configured.

When you press this button, a Berry .bec file is downloaded from http://ota.tasmota.com/tapp/leds_panel.bec, until next restart.

Note: the memory footprint is 17KB RAM when loading the panel, of 9KB if webserver_async is already solidified, for example if #define USE_BERRY_DEBUG is enabled.

Flash size impact: +120 bytes

Checklist:

• The pull request is done against the latest development branch
• Only relevant files were touched
• Only one feature/fix was added per PR and the code change compiles without warnings
• The code change is tested and works with Tasmota core ESP8266 V.2.7.8
• The code change is tested and works with Tasmota core ESP32 V.3.1.0.241206
• I accept the CLA.

NOTE: The code change must pass CI tests. Your PR cannot be merged unless tests pass