Replace Gradle single quote strings with the double quote form
whenever possible. The change helps to being consistency to the
dependencies section where mostly single quotes were used, but
occasionally double quotes were required due to `${}` references.
Rename the `spring-boot-cloudnativebuildpack` module to
`spring-boot-buildpack-platform` and update the the package
name to `org.springframework.boot.buildpack.platform`.
Closes gh-19851
Add a new `spring-boot-layertools` module which provides jarmode support
for working with layers. The module works with both classic fat jars,
as well as layered jars.
Closes gh-19849
Add a Java implementation of the buildpacks.io specification allowing
projects to be packaged into OCI containers. The `builder` class
provides a Java equivalent of `pack build` command and is based on
the `pack` CLI Go code published at https://github.com/buildpacks/pack.
Closes gh-19828
