Add `rapids-http-path` script

[ajschmidt8]

rapids-s3-path is currently the source of truth for computing proper paths for CI workflow artifacts.

The problem with rapids-s3-path is that it only returns S3 URIs (e.g. s3://rapids-downloads/ci/cudf/...).

There are a lot of different areas where we call rapids-s3-path and then replace s3://rapids-downloads/ with https://downloads.rapids.ai/:

• gha-tools/tools/_rapids-download-from-s3

  Line 18 in 71f9e9a

  s3_dl_path=$(echo "${s3_dl_path}" | sed "s|s3://${RAPIDS_DOWNLOADS_BUCKET}|https://${RAPIDS_DOWNLOADS_DOMAIN}|")

• gha-tools/tools/rapids-upload-to-s3

  Line 36 in 71f9e9a

  ARTIFACTS_URL=${browsable_url/s3:\/\/${RAPIDS_DOWNLOADS_BUCKET}\//https:\/\/downloads.rapids.ai\/}

• gha-tools/tools/rapids-upload-artifacts-dir

  Line 32 in 71f9e9a

  ARTIFACTS_URL=$(rapids-s3-path | sed "s|s3://${RAPIDS_DOWNLOADS_BUCKET}|https://${RAPIDS_DOWNLOADS_DOMAIN}|")

To prevent this manual replacement from being necessary, we should add a rapids-http-path script that computes the https://downloads.rapids.ai path.

The scripts should ultimately be refactored to work like this:

• _rapids-path - a new script that's called by rapids-s3-path and rapids-http-path to generate the URI path. This script is prefixed with an underscore (_) to denote that it's not intended by be used publicly (only by other gha-tools scripts).
• rapids-s3-path - should be refactored to call _rapids-path and prepend the s3://rapids-downloads/ string
• rapids-http-path - a new script that calls _rapids-path and prepends the https://downloads.rapids.ai/ string

[AyodeAwe]

Fixing in #72