fix!: Rename package to match name inferred from git URL

[jbelkins]

Issue #

Fixes #680

Description of changes

Since the introduction of SPM, a package manifest has included a field for providing a "declared" name (i.e. set in the name property of the Package structure) that is used in other manifests to identify a package as a dependency.

In SE-0226, Swift package naming was altered to derive the name from the Git URL for the package. While the preferred way to identify a dependency is by the inferred name, Package retained the declared name field to provide backward compatibility with dependencies declared before this improvement. (Note that referring to a package by its declared name is now deprecated, but use of deprecated APIs in a package manifest does not throw warnings.)

The rationale for this change is that it allows the package manager to resolve what dependencies it needs for a specific target without resorting to downloading every dependency referenced in a manifest to see what name is declared in each dependency's own manifest. In our case, the name that is inferred from this package's URL is aws-sdk-swift (essentially the last path component with extensions dropped).

Most other Swift packages have moved to (or been created with) a declared package name that matches the inferred name. While latest Swift tools allow a manifest to identify a package by either name, consistent naming brings the following advantages:

• Consumers who move to the inferred name will get the advantage of faster dependency resolution as promised by SE-0226.
• Certain common tools, such as swift package edit with the --path extension (which is used by Swift-VSCode's GUI package management tools), break when the declared name and the inferred name do not match.

This will cause a breaking change but the update to requiring package manifests will be trivial; package manifests need only require this package by the new/inferred name. I do not expect our Git URL to change, so this name will be permanent unless SPM changes naming conventions again.

Tested with:

• Corresponding name changes in smithy-swift and aws-crt-swift.
• A successful release build (see link here.)
• Successfully built/tested as a downstream by smithy-swift (se PR above).

Specific changes:

• Declared package name updated to match the inferred name
• codegen/Package.swift updated to use inferred naming
• scripts/generatePackageSwift.swift updated to render manifest with inferred naming
• Fix a few generated import statements which were importing by package name (which worked by coincidence until this name change)

New/existing dependencies impact assessment, if applicable

No new dependencies were added to this change.

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

[epau]

lgtm deferring to @ganeshnj though since this is a breaking change

[ganeshnj]

When we do the release with this change, we must create a discussion with code snippet to show how to migrate from old package name to aws-sdk-swift.

[jbelkins]

When we do the release with this change, we must create a discussion with code snippet to show how to migrate from old package name to aws-sdk-swift.

You mean in the release notes for the release?