PyEditor - process(code) ability

[WebReflection]

Description

After yesterday meeting with Tufts, we've realized the PyEditor has no way to process code same way the PyTerminal does.

This MR would like to expose the same API we have with the terminal, when the script with the type py-editor or mpy-editor actually gets attached a process field, among a target one when is not setup, where such process(code) will return a promise that resolves (or rejects) after the provided code has been evaluated.

Please note the evaluation won't automatically print results in the editor output as I think that might be undesired (but we could change that if needed / requested).

/cc @ntoll @JeffersGlass

Changes

• attach a method to the script that can pass along the code to evaluate to the interpreter
• notify bubbling up to the window (global) whenever a py-editor or an mpy-editor has been bootstrapped
• test that everything actually works as expected

Documentation / Example

<script>
addEventListener('mpy-editor', async event => {
  // the script is the target of this event
  const { target: script } = event;
  // it can process any Python code
  await script.process('globalValue = 123');
});
</script>
<script type="mpy-editor">
# run will show the previously setup value
print(globalValue) # 123
</script>

Once the mpy-editor event is triggered, if the script was a setup one, it will process code after the setup is complete. In every other case, it will process code either before the code in the editor has run at least once, or after such code run already, it's up to the user.

Checklist

• All tests pass locally
• I have updated CHANGELOG.md
• I have created documentation for this(if applicable)