[C++] Add bundled external project for aws-sdk-cpp #26087
Description
Currently build_awssdk errors with a FIXME message. We should fix it. aws-sdk-cpp is not widely available on package managers, and in some cases (like Homebrew) its cmake config is broken.
Reporter: Neal Richardson / @nealrichardson
Assignee: Neal Richardson / @nealrichardson
PRs and other links:
Note: This issue was originally created as ARROW-10068. Please see the migration documentation for further details.