Re-point those using `BuildError` from smithy-http to smithy-types (#3070)

## Motivation and Context
Completes #3054 (a follow-up on #3032)

## Description
#3032 moved `BuildError` from `aws_smithy_http::operation::error` to
`aws_smithy_types::error::operation`. That PR also left "breadcrumbs",
so that customers could still consume `BuldError` from `aws_smithy_http`
after the move.

This PR turns breadcrumbs into deprecation messages (via
`#[deprecated(...)]`) and updates existing places that used to use moved
types from `aws_smithy_http` to `aws_smithy_types`.

## Testing
Relied on tests in CI.

## Checklist
- [x] I have updated `CHANGELOG.next.toml` if I made changes to the
smithy-rs codegen or runtime crates

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Co-authored-by: Russell Cohen <rcoh@amazon.com>