Add `Accept-Encoding` when making API requests

[tesaguri]

This uses tower-http crate's Decompression middleware, which adds Accept-Encodings to the requests and transparently decodes the response bodies. It should significantly reduce network traffic.

The REST API supports the efficient br encoding but the Streaming API v1 supports the gzip encoding only, so I enabled both the encodings.

[tesaguri]

Upgraded tower-http to ^0.3.

The CI failure seems to be due to a dependency's MSRV bump and not to be related to this change.