Add automatic tests

**Depends on https://github.com/fenjalien/circuitypst/pull/2** Add new structure for automatic test and some use cases as well (inspired by typst-canvas structure): It includes two new workflows. - One that is executed automatically on push and pull request called "test" - One executed on demand called "update-tests" that can be used to generate the reference pngs and download them on the computer. Useful if the person is not able to launch the script locally. - The test case support multipage output. The test script automatically check all the output pngs versus the reference png committed with the repository.