Google Artifact Registry support for sbt and/or coursier

Adds handler for artifactregistry:// protocol to sbt and/or coursier.
Inspired by abdolence/sbt-gcs-resolver and 987Nabil/gar-coursier.

Supports artifactregistry only.
Splitted into modules that can also be used without sbt and/or only with coursier by adding a custom protocol handler.
Adds support for missing maven-metadata.xml.

Usage

To use the sbt plugin add to project/plugins.sbt:

lazy val garHandlerVersion = "0.1.4"

addSbtPlugin("dev.rolang" % "sbt-gar-handler" % garHandlerVersion)

// this is optional, add it if you have artifactregistry:// resolvers for build dependencies
csrConfiguration := csrConfiguration.value.withProtocolHandlerDependencies(
  Seq("dev.rolang" % "gar-coursier_2.13" % garHandlerVersion)
)

For publish settings in build.sbt use:

publishTo := Some(
  dev.rolang.sbt.gar.ArtifactRegistryIvyResolver.create(
    "My Registry", "https://${LOCATION}-maven.pkg.dev/${GCP_PROJECT}/maven"
  )
)

The plugin is automatically enabled for all projects and will install a global artifactregistry:// handler as well as adding the protocol handler to coursier.

To use with coursier only use the dev.rolang:gar-coursier_2.13 package.
Example usage via the coursier JVM CLI (ensure default google credentials are set up):

cs launch coursier:2.1.24 dev.rolang:gar-coursier_2.13:0.1.3 -- \
    resolve \
    -r '!artifactregistry://LOCATION-maven.pkg.dev/PROJECT/REPOSITORY' -r central \
    org:name:ver

Development

Run test

Ensure default google credentials are set up. Run:

// GetVersions test args: 1. maven root, 2. organization, 3. module name
sbt '++2.13; coursier/Test/runMain GetVersions asia-maven.pkg.dev/my-project/maven com.example my-package_2.13'

Publish local:

sbt '+publishLocal'