[BUG] Text-to-speech causes extension to crash in Opera

[owl-from-hogvarts]

What's wrong

Extension crashes when text is deselected. Issue comes from hidePopup method which unconditionally calls stopSpeaking. This in turn tries to access speechSynthesis object which is non-existent in Opera browser.

Stack Trace

 ``` Uncaught ReferenceError: speechSynthesis is not defined at stopSpeaking (user-script.js:27030:5) at Google.stopSpeaking (user-script.js:27216:9) at App.hidePopup (user-script.js:31701:63) at App.onMouseDown (user-script.js:31832:22) ```

Expected behavior

When text is deselected popup should hide without producing any errors

How to reproduce

1. Install Opera browser
2. Install the extension
3. Launch any web-site
4. Try to select text
5. Wait for popup to appear
6. Try clicking anywhere to hide popup
7. See that popup does not hide
8. Check browser's console to see error message

System information

XTranslate version: 3.3.2 Opera version: 110.0.5130.23 System: Arch Linux

I can provided more information on demand. I can't figure out right now what else can be useful.

[owl-from-hogvarts]

I propose a solution: check if text-to-speech is supported by browser and only then show try to work with it

[ixrock]

Opera not supported officially btw, lol. Free to open PR's for in separated branches / do own forks for Opera.

[ixrock]

This issue I believe is coming after this update: https://github.com/ixrock/XTranslate/commit/b121a83334874a15a452275b31caa7cec61942a2

[ixrock]

@owl-from-hogvarts I recommend to you also switch from opera to Brave / Chrome / Vivaldi. BTW I've been used opera since 6(or even 7) when it wasn't on chrome engine and stopped at some point, now it's more funny joke then a browser.