Update the golang.org/x/* deps (except for mobile)

[Jacalz]

Description:

Now that Go 1.17 is the lowest supported version, we can finally update the golang.org/x/* packages for various improvements and cleanups. The only one not updated was golang.org/x/mobile because I don't have any mobile device to test on and don't feel comfortable doing that update.

I have tested cmd/fyne and cmd/fyne_demo with these changes. Every update is in a separate commit and everything seems to be working as expected.

Checklist:

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

Where applicable:

• Updated the vendor folder (using go mod vendor).

[coveralls]

Coverage: 62.044%. Remained the same when pulling de29b05 on Jacalz:update-golang-x-deps into ec0d80e on fyne-io:develop.

[andydotxyz]

We probably need to figure out here the x/mobile is coming from as we have our internal fork so if both are compiled in we are wasting space.

[Jacalz]

We only seem to be using the golang.org/x/mobile/exp/f32 package within some goxjs file. Nothing else exists in the vendor folder. I went ahead and updating it as it was mostly just cleanups and formatting changes (https://github.com/golang/mobile/commits/master/exp/f32).

[Jacalz]

It is also worth noting that I don't think we have that package locally within the repository.