Add support for downloading all available versions of photos

[jcass77]

Breaking change

No breaking changes.

Proposed change

There appear to be more photo versions available on iCloud than pyicloud currently caters for. This PR:

1. makes the 'full', 'large', 'sidecar', and 'original_alt' photo resources and 'original_compl' video resource available for download as well.
2. if the user has edited a photo, then that version will be downloaded instead of the original unedited version.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New service (thank you!)
• New feature (which adds functionality to an existing service)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests
• Documentation or code sample

Example of code:

# There aren't any changes. The below still provides a list of the versions that are available for download.
photo.versions.keys()

# If an edited version of the photo is available on iCloud, then the below will download that version instead.
download = photo.download('original')

Additional information

• This PR fixes or closes issue: should fix Downloading photos downloads version with editions undone #323 and downstream [Latest Edits] Portrait photos or blurred backgrounds do not seem to be well preserved and downloaded. icloud-photos-downloader/icloud_photos_downloader#249
• This PR is related to issue: Improves and replaces Adding alternative resOriginalAlt version to Photos #340

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated to README

[hirenr]

Any idea when this would merge?

[jcass77]

Rebased on the master branch.