The self voicing enactor throws error when using UIO+ with wikipedia

[cindyli]

Describe the bug

The self voicing enactor throws error when using UIO+ with wikipedia pages.

To reproduce

Steps to reproduce the behavior:

1. In the UIO+ source code, modify "uioPlus.enactor.selfVoicing" in enactors.js to remove the distributeOptions block that disables the page level reading in the self voicing component;
2. In a terminal, run "npm run build". Install the built UIO+ in Chrome.
3. In Chrome, open https://en.wikipedia.org/wiki/Main_Page, turn on text-to-speech, click "play" button;
4. In the browser console, lang is undefined error is thrown.

Expected behavior

The error should not occur.

Technical details

After a debugging, this error is originated from [this line in Orator.js|https://github.com/fluid-project/infusion/blob/main/src/components/orator/js/Orator.js#L681] because parsedBlock is an empty array so parsedBlock[0].lang is undefined. The reason that an empty array of parsedBlock is pushed into that.parseQueue is from [this block|https://github.com/fluid-project/infusion/blob/main/src/components/orator/js/Orator.js#L572-L574]. On the wikipedia page, many text blocks fit into this condition (lastQueue.length && lastQueue[0].lang !== lang). Those blocks have text but in a different language from what's defined at the page level.

Additional context or notes

This issue is also filed against the infusion at https://issues.fluidproject.org/browse/FLUID-6760