Add automatic tests

[flavio20002]

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.