feat!(webui): Enhance WebUI + new REST API /process_data

[Slider0007]

• Reduce overview page loading time and consistent data presentation by
  • providing all needed data with only one REST API call /process_data
  • preload configuration file (config.ini) already in header of index.html and parse only needed parameter
• Add new REST API /process_data to firmware

{
	"api_name":	        "handler_process_data",
	"timestamp_processed":	"NOT YET SUPPORTED",
	"timestamp_valid":	"main\t2023-07-30T14:45:58+0200\r\ntest\t2023-07-30T14:45:58+0200",
	"actual_value":	        "main\t530.01137\r\ntest\t0",
	"pre_value":	        "main\t530.01137\r\ntest\t0",
	"raw_value":	        "main\t0530.01137\r\ntest\t0",
	"value_status":	        "main\tno error\r\ntest\tno error",
	"rate_per_min":	        "main\t-0.100141\r\ntest\t0.000000",
	"rate_per_round":	"main\t-0.27038\r\ntest\t0",
	"process_state":	"[14:45:58] Publish to MQTT",
	"process_error":	"0",
	"temperature":	        "45",
	"rssi":	                "-59",
	"uptime":	        "  0d 00h 00m 49s",
	"round_counter":	"1"
}

• Updated webpage title naming and arragement to be better conform with smaller screens
  
• Add indication to webpage that this is a fork
• Add additional webpage shortcut icons
  -> inspired by Shortcut Icon hinzugefügt  jomjol/AI-on-the-edge-device#2530 and @pfeifferch
• Load tflite list only once and in global variable
• Increased HTTP server wait time (15s)
• Keep overview image max at original size without parsing config.ini (only by CSS)
• Updated OTA page
• Cleanup not needed webserver context variables

---

⚠️ ATTENTION - BREAKING CHANGE

• Legacy REST APIs removed
  • /setPreValue.html
  • /statusflow.html
  • /cputemp.html
  • /rssi.html

BEGIN_COMMIT_OVERRIDE
feat(webui): Enahnce WebUI using new REST API /process_data and some further chnages
feat!(webui): Remove legacy REST APIs
END_COMMIT_OVERRIDE