feat(ci): support parallel execution

[matejchalk]

Closes #887

• Added parallel option (disabled by default), which is forward to each monorepo tool's "run many" CLI command.
• For known monorepo tools, reports are collected in bulk instead of individually per project.
  • Because this all-in-one execution doesn't allow setting different output directories per project via CLI arguments, each project's output directory is resolved using print-config command.
    • This makes the output option obsolete, so it's been removed.
    • It is now responsibility of the user to ensure projects' outputs don't clash.
• Added E2E tests for monorepo mode - runs on real Nx monorepo in parallel mode, as well as on npm workspaces workspaces (other tools would require additional dependencies and environment setup).
• Added integration tests for all the main variations of monorepo mode - runs on real file system, but code-pushup commands are mocked.
• Added unit tests for individual tool handlers.

[github-actions]

Code PushUp

🤨 Code PushUp report has both improvements and regressions – compared target commit 48c594e with source commit 9099514.

🕵️ See full comparison in Code PushUp portal 🔍

🏷️ Categories

🏷️ Category	⭐ Previous score	⭐ Current score	🔄 Score change
Performance	🟡 54	🔴 48
Code coverage	🟢 90	🟢 91
Security	🟡 82	🟡 81
Updates	🟡 74	🟡 74	–
Accessibility	🟢 91	🟢 91	–
Best Practices	🟢 100	🟢 100	–
SEO	🟡 61	🟡 61	–
Bug prevention	🟢 100	🟢 100	–
Code style	🟢 100	🟢 100	–

👍 1 group improved, 👎 2 groups regressed, 👍 3 audits improved, 👎 6 audits regressed, 12 audits changed without impacting score

🗃️ Groups

🔌 Plugin	🗃️ Group	⭐ Previous score	⭐ Current score	🔄 Score change
Lighthouse	Performance	🟡 54	🔴 48
Code coverage	Code coverage metrics	🟢 90	🟢 91
JS Packages	NPM audit	🟡 82	🟡 81

14 other groups are unchanged.

🛡️ Audits

🔌 Plugin	🛡️ Audit	📏 Previous value	📏 Current value	🔄 Value change
Lighthouse	Largest Contentful Paint	🟨 3.2 s	🟨 3.8 s
Lighthouse	Time to Interactive	🟥 13.3 s	🟥 19.1 s
Lighthouse	Speed Index	🟨 5.7 s	🟥 6.1 s
Lighthouse	First Contentful Paint	🟨 2.9 s	🟥 3.1 s
JS Packages	Vulnerabilities for NPM dev dependencies.	🟥 12 vulnerabilities (6 high, 4 moderate, 2 low)	🟥 13 vulnerabilities (6 high, 4 moderate, 3 low)
Lighthouse	Total Blocking Time	🟥 3,530 ms	🟥 9,210 ms
Code coverage	Line coverage	🟩 90.6 %	🟩 91.1 %
Code coverage	Branch coverage	🟨 85.2 %	🟨 85.7 %
Code coverage	Function coverage	🟩 92.9 %	🟩 93.4 %
Lighthouse	Minimizes main-thread work	🟥 13.4 s	🟥 22.8 s
Lighthouse	Avoids enormous network payloads	🟩 Total size was 1,820 KiB	🟩 Total size was 1,813 KiB
Lighthouse	JavaScript execution time	🟥 6.3 s	🟥 12.6 s
Lighthouse	Metrics	🟩 100%	🟩 100%
Lighthouse	Max Potential First Input Delay	🟥 1,600 ms	🟥 3,690 ms
Lighthouse	Uses efficient cache policy on static assets	🟨 28 resources found	🟨 28 resources found
Lighthouse	Server Backend Latencies	🟩 330 ms	🟩 140 ms
Lighthouse	Initial server response time was short	🟩 Root document took 520 ms	🟩 Root document took 340 ms
Lighthouse	Eliminate render-blocking resources	🟥 Potential savings of 1,120 ms	🟥 Potential savings of 1,240 ms
Lighthouse	Network Round Trip Times	🟩 80 ms	🟩 20 ms
Lighthouse	Reduce unused CSS	🟥 Potential savings of 96 KiB	🟥 Potential savings of 67 KiB
JS Packages	Outdated NPM prod dependencies.	🟨 9 outdated package versions (5 major, 2 minor, 2 patch)	🟨 10 outdated package versions (5 major, 4 minor, 1 patch)

487 other audits are unchanged.