Add pico-sdk support

[Prime9999]

Enable pico-sdk (not arduino-pico) to use LovyanGFX with CMake.
See also: examples_for_picosdk/* .

[tobozo]

hi, thanks for your contribution 👍

fix esp-idf build

⚠️ apparent reason for esp-idf build failing: esp-idf doesn't find esp-idf.cmake file

CMake Error at /home/runner/work/LovyanGFX/LovyanGFX/CMakeLists.txt:3
  (include):
    include could not find requested file:
      boards.cmake/esp-idf.cmake

solution 1: bring back the esp-idf cmake block into the CMakeLists.txt file
solution 2: (although I'm not sure it'll work) prepend ${COMPONENT_DIR} to the include directive:

    include(${COMPONENT_DIR}/boards.cmake/esp-idf.cmake)

github CI test suite

an extra CI build profile (pico-baremetal?) should be created for this situation, so any incidence (such as esp-idf choking on CMakeLists.txt) can be detected early.

I'll take care of adding this new profile to the github workflows but I'll need additional info.

• if using platformio then I'll need you to share your platformio.ini file so I can later add an extra entry to this file.
• if not using platformio I'll need a description of the required steps (pico-sdk version, url, save path, compile command) to reproduce when building both i2c and spi examples.

code density

This PR creates two additional copies of party parrot data, which isn't optimal as it impacts the overall size of the library archive

using a lighter example and/or creating a shared main.cpp file is recommended.

[tobozo]

all compilation tests succeeded, thanks again for your contribution ! 👍

leaving this here for posterity, this is the script I've used to test this PR locally:

export WORKSPACE=LovyanGFX/examples_for_picosdk
export PROJECTDIR=$WORKSPACE/i2c

export PICO_SDK_PATH="$(pwd)/pico-sdk"
export PICO_SDK_EXTRAS_PATH="$(pwd)/pico-extras"
export PICO_PLATFORM="rp2350"

git clone -b develop https://github.com/Prime9999/LovyanGFX
git clone -b master --depth 1 https://github.com/raspberrypi/pico-sdk
git clone -b master --depth 1 https://github.com/raspberrypi/pico-extras

cd pico-sdk
git submodule update --init
cd ..

cp $PICO_SDK_PATH/external/pico_sdk_import.cmake $WORKSPACE/pico_sdk_import.cmake
cp $PICO_SDK_EXTRAS_PATH/external/pico_extras_import.cmake $WORKSPACE/pico_extras_import_optional.cmake

cd $PROJECTDIR
ln -sv ../../../LovyanGFX LovyanGFX

mkdir -p build
cd build
cmake ..
make -j $(nproc)