Move swiftly from SwiftFormat to swift-format

[cmcgee1024]

The swiftlang organization is standardizing on swift-format for all of the projects since it is based on swift-syntax. It will be good to align swiftly with the rest of the organization.

First, we'll need to find a configuration that most closely matches our Swiftformat configuration in .swiftformat at the version that we are currently using.

Next step is to sweep the code with the new format for the various edge cases that cannot be aligned completely.

Finally, the swift-format should be added to the project dependencies, replacing SwiftFormat if it is already there, add instructions on how to use the new formatter, and align the CI soundness (lint.docker) on the new formatter.

[kkebo]

swift-format has been bundled in the toolchain since Swift 6.0, so we don't need any project dependencies if we use swift-format.

[adam-fowler]

swift-format has been bundled in the toolchain since Swift 6.0, so we don't need any project dependencies if we use swift-format.

Just like to point out, swift 6 hasn't actual been released yet

[cmcgee1024]

Mark this as release candidate, but we can remove that tag if this isn't a priority.