Add swift-argument-parser

[clackary]

Pull Request Description

Add https://github.com/apple/swift-argument-parser

Acceptance Criteria

• be an Xcode or swift package manager project
• support building on either Linux or macOS
• target Linux, macOS, or iOS/tvOS/watchOS device
• be contained in a publicly accessible git repository
• maintain a project branch that builds against Swift 4.0 and passes any unit tests
• have maintainers who will commit to resolve issues in a timely manner
• be compatible with the latest GM/Beta versions of Xcode and swiftpm
• add value not already included in the suite
• be licensed with one of the following permissive licenses:
  • Apache License, version 2.0
• pass ./project_precommit_check script run

PASS: swift-argument-parser, 5.2, 41f5fe, Swift Package
========================================
Action Summary:
     Passed: 1
     Failed: 0
    XFailed: 0
    UPassed: 0
      Total: 1
========================================
Repository Summary:
      Total: 1
========================================
Result: PASS
========================================
--- swift-argument-parser checked successfully against Swift 5.2 ---

[clackary]

@natecook1000 FYI - Also adding you as maintainer here! Thanks

[clackary]

@swift-ci test

[shahmishal]

Can you also add tag "tags": "swiftpm"?

[clackary]

@swift-ci test

[clackary]

@swift-ci test

[shahmishal]

This contains only the merge conflict fix, and the previous commit was tested successfully.

Also, json format was verified in the current trigger.

./swift-source-compat-suite/utils/format_projects_list.py swift-source-compat-suite/projects.json

merging the PR.