Signed-off-by: Daniel Mikusa <[email protected]>

Signed-off-by: Daniel Mikusa <[email protected]>

1. By default, we now pass
2. By default, we provide three possible plans all of which only provide (one provides just maven, one provides just a built app, one provides maven and a built app)
3. If a pom.xml file exists, then we add a requires (jdk, syft, maven).

This enables more scenarios:

1. All we do is install Maven. In this case, the build plan will provide maven and some other build pack will need to require it.
2. All we do is build with Maven. In this case, something else needs to provide maven & jdk.
3. Both install and build with Maven. This the classic case that we've been supporting.

Signed-off-by: Daniel Mikusa <[email protected]>

Based on what is in the buildplan, the buildpack can now optionally install and optionally build.

If `maven` is in the buildplan, then the buildpack will attempt to install or validate that Maven is installed and generate a command to run Maven.

This comes in four forms:

1. Install Maven Daemon
2. Install Maven
3. Validate Maven Wrapper
4. Validate Maven on $PATH

If `jvm-application-package` is in the buildplan, then the buildpack will attempt to perform a build with Maven. This uses the command from the previously installed or validated Maven.

This enables four scenarios:

1. The buildpack installs & runs Maven (or Maven Daemon)
2. The buildpack runs Maven w/Maven Wrapper
2. The buildpack just installs Maven (or Maven Daemon)
3. The buildpack doesn't install Maven or use Maven Wrapper, but just runs Maven (Maven is provided through other means)

Signed-off-by: Daniel Mikusa <[email protected]>

Signed-off-by: Daniel Mikusa <[email protected]>

- Added a case for default pom.xml location as well as a custom location when the file does not exist
- Fixed descriptions & added context for additional grouping

Signed-off-by: Daniel Mikusa <[email protected]>