v23: bug fixes, sample rates, and openevv updates

This release fixes a bug where NVDA could become silent for those of you using activity profiles, or addons like nvda-multilanguage, that cause NVDA to rapidly switch synthesizers.

It also targets the latest release of openevv, with a collection of bugfixes from them. However, openevv is still defaulted to off, and is only recommended for early testing, not daily use.

Oh, and one final thing: the addon now allows choosing sample rates from within NVDA speech settings. This prepares us for when OpenEVV adds support for sample rates higher than the default, as well as for future work on sample rates from @Nick6489. At the moment, though, it's not that interesting unless you want 8khz for some reason.