Features/windows gopherjs

[Bluebugs]

Description:

Properly warn user about gopherjs limitation on Windows.

Fixes #3161

Checklist:

• Tests included.
• Lint and formatter run with no errors.
• Tests all pass.

Where applicable:

• Public APIs match existing style and have Since: line.
• Any breaking changes have a deprecation path or have been discussed.
• Updated the vendor folder (using go mod vendor).
• Check for binary size increases when importing new modules.

[coveralls]

Coverage decreased (-0.04%) to 61.349% when pulling 72fd0b5 on Bluebugs:features/windows-gopherjs into 423d71f on fyne-io:develop.

[Jacalz]

I don’t have any Windows computer to test it on at the moment but the code seems good and tests pass

[Bluebugs]

I don’t have any Windows computer to test it on at the moment but the code seems good and tests pass

I have run manual test (on top of the automated one). It would have been nice if someone else was able to test too, but I guess merging it in develop and getting feedback during the release cycle is more likely to work in this case.