Add support for `download` function in web

[mbfakourii]

New Pull Request Checklist

• [x] I have read the Documentation
• [x] I have searched for a similar pull request in the project and found none
• [x] I have updated this branch with the latest main branch to avoid conflicts (via merge from master or rebase)
• [ ] I have added the required tests to prove the fix/feature I'm adding
• [ ] I have updated the documentation (if necessary)
• [ ] I have run the tests without failures
• [ ] I have updated the CHANGELOG.md in the corresponding package

Additional context and info

In this PR, download support was added to dio with the help of Blob files.

Note: There is no need to send savePath on the web and it can be empty.