Fix _RowsReader for NVDA 2021.1

[lukaszgo1]

nvaccess/nvda#12251 refactored sayAllHandler and moved its content to speech.sayAll - this broke _RowsReader. This PR makes _RowsReader ready for NVDA 2021.1. While at it I've made sure that priorities are imported from speech.priorities and removed runSilently which was not used any longer and therefore it was quite likely it would not be kept uptodate with the changes in NVDA - it can always be seen in the repository log.

[ABuffEr]

Hi @lukaszgo1 ,
thanks, as usual.
I'm thinking to release a stable version, then cleaning code making it compatible only with 2021.1 and above. Ensuring retro-compatibility is getting tricky.

[lukaszgo1]

I'm thinking to release a stable version,

Having a stable release would be appreciated indeed.

then cleaning code making it compatible only with 2021.1 and above. Ensuring retro-compatibility is getting tricky.

Is this really necessary? As far as I can tell there would be no more breaking changes until 2022.1 so what we have now is going to work for at least another year and then we can reconsider. I'm privately pretty interested in CR working at least back to 2019.2 and I'm willing to keep it compatible.

What is annoying is the fact that we don't have any user statistics to measure how many people are using Columns Review with a given release of NVDA and we're unlikely to be able to collect them any time soon.