enable eslint and prettier for exercise-src/react-native in CI
use global React namespace rather than import, following community conventions
don't use import type, just keep all imports together
in exercise code (but not in the app itself): sort imports neatly via eslint rule (keeps diffs clean)
make typecheck pass in all solutions (can't automate yet), except for some calls to navigation.navigate which will be fixed with the navigation-params fixes
Changes:
test,test:watch, andtest:inspecteslintandprettierforexercise-src/react-nativein CIReactnamespace rather than import, following community conventionsimport type, just keep all imports togethertypecheckpass in all solutions (can't automate yet), except for some calls tonavigation.navigatewhich will be fixed with the navigation-params fixesundefinednotnull