Support legacy Gradle lockfiles

[maxrake]

Overview

Gradle versions prior to v7 produce lockfiles differently than the newer v7 and v8 releases. These legacy versions produce multiple lockfiles and store them in a gradle/dependency-locks directory with *.lockfile names. Each file is named by the configuration it locks and has the lockfile extension. The CLI, parser, and lockfile generator should be updated to account for these legacy Gradle lockfiles.

Additional Info

Possible CLI changes required:

• Lockfile identification, here
  • lockfile/src/java.rs
• Lockfile parsing, if the format for older versions is different
  • lockfile/src/parsers/gradle_dep.rs
• Lockfile generation, for the lockfile_path plus maybe some other differences
  • lockfile_generator/src/gradle.rs
• Documentation
  • docs/supported_lockfiles.md
• New test fixture(s) for older version of this lockfile

Resources

• Gradle v5.5.1 dependency locking documentation
• Gradle v6 dependency locking documentation
• PR where the format/options changed

Questions

• Are versions of Gradle prior to v6 targeted for inclusion in this issue?
  • Answer: Yes. Specifically v5.5.1 and newer.
• If an older version of gradle is in use and a lockfile does not exist for the CLI to parse, should the lockfile generator be updated (if needed) to ensure it creates a lockfile in the older/matching format?
  • It appears the command for generating lockfiles has remained constant: gradle dependencies --write-locks
  • Still need to confirm if the --init-script option is also consistent
• Can we get real-world examples of lockfiles generated with Gradle v6?

Acceptance Criteria

• [x] Lockfiles generated with Gradle v5 are recognized
• [x] Lockfiles generated with Gradle v5 can be parsed
• [ ] Lockfiles generated with Gradle v6 are recognized
• [ ] Lockfiles generated with Gradle v6 can be parsed
• [x] Lockfiles generated with Gradle v7 and v8 continue to be recognized and parsed
• [x] ~Test fixture(s) are added to account for the older format~
  • The format did not change, only the path/name
• [x] Documentation is updated to reflect the additional supported lockfile(s)