Don't block an app's main thread when sending typed characters to NVDA (#11425)
* Ensure an app's main thread does not block when notifying NVDA about typed characters.
* use constants for some literal values.
* nvdaControllerInternal_typedCharacterNotify: don't take threadID as an argument as it is never used.
* Fix typo in comment
* Fix linting issues
* fix typo
* Fix typo
Co-authored-by: Leonard de Ruijter <leonardder@users.noreply.github.com>
* Address review comments
Co-authored-by: Leonard de Ruijter <leonardder@users.noreply.github.com>