Support uploading files with Size filtering and AQL avoiding

[sverdlov93]

• All tests passed. If this feature is not already covered by the tests, I added new tests.
• All static analysis checks passed.
• This pull request is on the dev branch.
• I used gofmt for formatting the code before submitting the pull request.

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• Added Sha256 and Size fields to DownloadParams to avoid fetching them with AQL
• Following this change added support for checksum validation for sha256 and united the checksum validation code.
• Added SizeThreshold field to support filtering files by size.
• Improved the ListFiles func, before it was first collecting all files and then running on them again to filter. Now it's filtering the files while collecting them.
• Also added support for filtering by size threshold.