Implement chunk upload

Add MultipartUploadService. It is used to upload files larger than 50 MB. Add HashService which is used to generate the hash for a file.

When the zipped project is bigger than 50 MB we often receive ECONNRESET error as such big file cannot be uploaded. So we upload it by chunks by using the server api. The file is validated with its hash, so we calculate it and send it to the completeUpload call. Currently the server does not verify each chunk hash.

Add tests for MultipartUploadService and HashService.
Unfortunately I cannot override default autogenerated code (we were discussing the idea to have another file with correct server-api call and import it in the bootstrap after the real one, but this cannot work). The problem is that I have to pass headers which are different for each chunk, so I have to pass another parameter to uploadChunk method of IUploadServiceContract (which means to override autogenerated code). For the moment I've added a test that verifies we are using correct upload method (not the autogenerated one) in our MultipartUploadService.