feat(device_info_plus): add storage information

[Binozo]

Description

Added storage info (total and free disk space) for Android and iOS.

Related Issues

None

Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I titled the PR using Conventional Commits.
• I did not modify the CHANGELOG.md nor the plugin version in pubspec.yaml files.
• All existing and new tests are passing.
• The analyzer (flutter analyze) does not report any problems on my PR.

Breaking Change

No

• Yes, this is a breaking change (please indicate that with a ! in the title as explained in Conventional Commits).
• No, this is not a breaking change.

[Binozo]

Hmm iOS integration test timed out but everything else seems fine

[miquelbeltran]

Also looks good to me. I want to test on devices before merging. Don't worry about simulator/emulators, we have had problems with those jobs and we need to fix them someday.

[Binozo]

Hey @miquelbeltran, did you have time to test this? Can I help somehow? 🙂

[miquelbeltran]

Sorry @Binozo, I've been busy with the SharePlus refactor PR, I'll try to get to this asap

[miquelbeltran]

I tested on iOS and it seems fine, but I need to request a couple of changes that I missed on my first look at the code:

1. The Android and iOS params are named differently, one is totalFreeSpace and the other is totalFreeSize, I'd prefer if the naming was consistent (or is there a reason for this?)
2. The new params are missing in the example, they should be added as well.

Thanks again and sorry for the delay reviewing