Add Arduino lib to arduino as IDF component

[me-no-dev]

Redo of: #8115

This Doc update is based on "for reference" issue #7839
This update provides info on how to add Arduino library when using arduino-esp32 as an ESP_IDF component.
There is also new script in tools/add_lib.sh which helps with that. The script also creates the CMakefileLists.txt

Usage of the script:

This script help to add library when using arduino-esp32 as an ESP-IDF component
The script accepts up to three arguments:
-n  NEW: URL address to new library on GIThub (cannot be combined with -e)
-l  LOCAL: Path to the project where the library should be placed locally (must be paired with -e or -n)
-e  EXISTING: path to existing libary- this will simply skip the download (cannot be combined with -n)

Examples:
./add_lib.sh -n https://github.com/me-no-dev/ESPAsyncWebServer
./add_lib.sh -l ~/esp/esp-idf/examples/your_project
./add_lib.sh -e ~/Arduino/libraries/existing_library

./add_lib.sh -n https://github.com/me-no-dev/ESPAsyncWebServer -l ~/esp/esp-idf/examples/your_project
./add_lib.sh -e ~/Arduino/libraries/existing_library -l ~/esp/esp-idf/examples/your_project"

The script was tested with this (manually checked the results):

#!/bin/bash

# test all possible combinations of parameters for the add_lib.sh script

# define test cases
test_cases=(
    "-n https://github.com/me-no-dev/ESPAsyncWebServer -l ~/esp/esp-idf/examples/add_lib"
    "-n https://github.com/me-no-dev/ESPAsyncWebServer -e ~/Arduino/libraries/ESPAsyncWebSrv"
    "-l ~/esp/esp-idf/examples/add_lib -e ~/Arduino/libraries/ESPAsyncWebSrv"
    "-n https://github.com/me-no-dev/ESPAsyncWebServer -l ~/esp/esp-idf/examples/add_lib -e ~/Arduino/libraries/ESPAsyncWebSrv"
    "-n https://github.com/me-no-dev/ESPAsyncWebServer -e ~/nonexistent/folder"
    "-n https://github.com/me-no-dev/ESPAsyncWebServer"
    "-l ~/esp/esp-idf/examples/add_lib"
    "-e ~/Arduino/libraries/ESPAsyncWebSrv"
)

# run each test case
for test_case in "${test_cases[@]}"; do
    echo "Running test case: ./add_lib.sh $test_case"
    ./add_lib.sh $test_case
    if [ $? -eq 1 ]; then
        echo "Test case failed: $test_case"
    else
        echo "Test case passed: $test_case"
    fi
    echo "============================================="
done