Fix flutter test path to realm_dart.dll

[desistefanova]

When running flutter tests on windows an error appears that realm_dart.dll can not be loaded. It is because executable path for flutter tests is not in the local app directory. The same problem exists also on Linux and MacOS.

[desistefanova]

This should not be needed. Lets investigate why is this happening.

The executable file for Flutter is: \realm-dart\flutter\realm_flutter\example\build\windows\runner\Debug\realm_example.exe and it is able to find the realm_dart.dll by name only. But when we run the flutter tests the executable file is: \flutter\bin\cache\artifacts\engine\windows-x64\flutter_tester.exe then realm_dart.dll can not be loaded by name only. We need to pass the whole path from the current folder. "./build/windows/runner/Debug/$binaryName.dll";

[nirinchev]

Why does this work on CI then? 🤔

[desistefanova]

Why does this work on CI then? 🤔 Command dart test -r expanded -j 1 is not FlutterPlatform and the path that is returned is "binary/windows/realm_dart.dll". Command flutter drive -d windows --target=test_driver/app.dart --suppress-analytics --dart-entrypoint-args="" has executable path \realm-dart\flutter\realm_flutter\tests\build\windows\runner\Debug\tests.exe and realm_dart.dll is in the same folder, that's why it is found only by name.

[desistefanova]

Windows:

MacOS:

Linux:

[desistefanova]

Linked to a task. Will be implemented in a new PR.