[ISSUE] Streaming buffer size is not easily configurable

[ksafonov-db]

Description

When downloading file contents, Files API initializes streaming buffer size = 1 Mb. This parameter is passed to requests library and then to underlying urllib3 code and controls the amount we're reading from the network stream. This parameter is not easily configurable by the user.

Reproduction

resp = client().files.download(path)
resp.contents.read()

Expected behavior

Client should be able to pass this parameter as a standard config option.
Internally, this config option will be the common source of truth for streaming buffer size.

Is it a regression?
No