Recognise only blockquotes followed by space

[robertKozik]

This PR changes quote regex to enforce following space after >.
> not followed by space won't be parsed as quote. In the multiple level quote context spaces between > signs are irrelevent

Fixed Issues

$ Expensify/App#41696

Tests

1. What unit/integration tests cover your change? What autoQA tests cover your change?
   I've Adjusted already present unit tests
2. What tests did you perform that validates your changed worked?
   I've run unit tests and checked the changes in both example app of react-native-live-markdown and E/App itself, by bumping the expensify-common version to my branch head

QA

1. What does QA need to do to validate your changes?
   bump expensify-common version in E/App and use chat normally - sent messages should be parsed with the new rule
2. What areas to they need to test for regressions?
   All quotes usage are vulnerable to regressions

[thienlnam]

Thanks, this looks good - could we also add tests for the negative case where the >hello doesn't turn into a blockquote?

[robertKozik]

Sure, I'm on it 👀

[thienlnam]

Awesome, thanks!