Improve GCP uploading

[minguyen9988]

thanks Andrew W for the contribution.

The PR include 2 fix:

• GCP upload need to return the error, currently it cannot catch upload error and retry, because the error is handle in defer and never return to caller, so it will fail at the first failure.
• Add support for HTTP reverse proxy handling, if the flag force_http is set to true it will use http reverse proxy.

[aadant]

@Slach do you mind reviewing this ?

[Slach]

@minguyen9988 please renew cli snapshot

clear && rm -fv ./test/testflows/clickhouse_backup/tests/snapshots/cli.py.cli.snapshot && RUN_TESTS="/clickhouse backup/cli*" ./test/testflows/run.sh

[minguyen9988]

ok I will do it before the next PR