Dju/yazali setup

[djudjuu]

• see new yazali.md file for documentation on setup
• added kyc-methods to KYCDecentroClient
• tests

should not be merged until we decide whether we want to handle yazali on a different master-branch

• [x] yarn test with swarmai development branch passes

[gparuthi]

I improved our dropzone to be more generalizable for future PRs