Add option to use path with spaces

[umbynos]

@per1234 added an input that takes arbitrary flags that are passed to Arduino CLI during compilation, maybe can be useful.
The problem arises from arduino/arduino-cli#1570

[per1234]

Thanks for your suggestion @umbynos. Since this is only relevant for testing Arduino boards platforms, which are not so plentiful as standalone libraries and sketches, I don't think it is worth adding an explicit path quoting check capability to arduino/compile-sketches.

Instead, the boards platform maintainers who want this should configure it in their workflow, using the action's existing general purpose cli-compile-flags input.

Here's an example of how that would be done: arduino/ArduinoCore-mbed#435