Keep Windows terminal open on error

If scrcpy is launched by double-clicking scrcpy.exe in Windows Explorer,
automatically set --pause-on-exit=if-error.

Without this, the terminal would close immediately, preventing the user
from seeing the error.

Also remove scrcpy-console.bat, which is now useless.

PR #6667 <https://github.com/Genymobile/scrcpy/pull/6667>