implement bulk hash (base64) check for import/upload of assets.

[maartenla]

I was migrating from GPhotos to Immich and had issues with the CLI tool.
I think the CLI needs some cleanup so that people can more easily migrate from GPhotos to Immich.
The biggest issue is the deprecated duplication checking, which doesn't work well if you have been running GPhotos and Immich next to each other.
I wanted to fix them and then noticed that #88 already fixes the issue.

Unfortunately that PR is very old, I tried to make it work by merging master but it's almost a whole rewrite.
So I branched master and added only the hashing parts.

Changes compared to the other PR by @etnoy

• The hashing is base64 instead of hex in the other PR.
• A progress bar for the hashing has also been added
• If the server returns a duplication error on upload it will be shown to the user at the end of the process.

I have tested this with my 30000 photos GPhotos backup.
Steps to check the duplication checking:

1. Upload images via CLI
2. Delete 1 or more images on Immich
3. Upload the same images via CLI and it will tell you there are duplicates.