RequestClient (companion-client) doesn't support retry mechanism customization

[maxibrain]

Initial checklist

• I understand this is a bug report and questions should be posted in the Community Forum
• I searched issues and couldn’t find anything (or linked relevant results below)

Link to runnable example

No response

Steps to reproduce

Analyze the source code:

uppy/packages/@uppy/companion-client/src/RequestClient.ts

Line 298 in f331622

retries: retryCount,

Expected behavior

I expect I am able to provide:

1. error handling callback to decide whether to abort uploading
2. retry callback to decide whether to keep trying to upload
3. max attempts number

Actual behavior

The current implementation lets me customize neither retry mechanism nor error handling. For example, if my upload endpoint returns validation error during the process it will start over and over again for 10 times defined as a constant in the code.