test: add integration tests for CLI client

[reedham-aws]

Integration test PR for buildkit/container CLI support.

Added a few parameterized tests for some image based tests, as well as just general tests for using the --use-buildkit flag. Worth noting is that when using the CLI, there were a lot of resource warnings that the sockets were being left open. I couldn't figure out a fix to this, but I think they're harmless warnings so I ignored them.

Implementation PR: #8661.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[roger-zhangg]

prob need to merge from develop for the chardet thing

[roger-zhangg]

would suggest to add a ARM64 test, and then mark one test -> x86/arm64 as https://github.com/aws/aws-sam-cli/blob/develop/CONTRIBUTING.md#tier-1-cross-platform-smoke-tests for running that test on finch / windows (to be added)

[reedham-aws]

would suggest to add a ARM64 test, and then mark one test -> x86/arm64 as https://github.com/aws/aws-sam-cli/blob/develop/CONTRIBUTING.md#tier-1-cross-platform-smoke-tests for running that test on finch / windows (to be added)

Done, I added as tier1, although not sure if this would have fallen more into the tier1_extra category. I think the testing of the CLI is important enough, not sure about the parameters.

[reedham-aws]

Integ test run: https://github.com/aws/aws-sam-cli/actions/runs/22508505787