feat(utils): support GitLab report links

[hanna-skryl]

Closes #722

This PR adds support for generating GitLab links in markdown reports when running in GitLab CI/CD, using predefined environment variables. It also refactors the environment detection logic to use a centralized environmentChecks record.

[github-actions]

Code PushUp

🤨 Code PushUp report has both improvements and regressions – compared target commit d902c2b with source commit c420a68.

🕵️ See full comparison in Code PushUp portal 🔍

🏷️ Categories

🏷️ Category	⭐ Previous score	⭐ Current score	🔄 Score change
Performance	🟡 52	🔴 47
Code coverage	🟢 90	🟢 90
Custom checks	🟡 67	🟡 67	–
Security	🟡 82	🟡 82	–
Updates	🟡 77	🟡 77	–
Accessibility	🟢 91	🟢 91	–
Best Practices	🟢 100	🟢 100	–
SEO	🟡 61	🟡 61	–
Bug prevention	🟢 100	🟢 100	–
Code style	🟢 99	🟢 99	–

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

🗃️ Groups

🔌 Plugin	🗃️ Group	⭐ Previous score	⭐ Current score	🔄 Score change
Lighthouse	Performance	🟡 52	🔴 47
Code coverage	Code coverage metrics	🟢 90	🟢 90

18 other groups are unchanged.

🛡️ Audits

🔌 Plugin	🛡️ Audit	📏 Previous value	📏 Current value	🔄 Value change
Lighthouse	Largest Contentful Paint	🟨 3.2 s	🟨 3.7 s
Lighthouse	Speed Index	🟥 6.4 s	🟥 7.0 s
Lighthouse	First Contentful Paint	🟥 3.2 s	🟥 3.3 s
Lighthouse	First Meaningful Paint	🟨 3.2 s	🟨 3.3 s
Lighthouse	Time to Interactive	🟥 19.6 s	🟥 18.4 s
Code coverage	Branch coverage	🟨 85.4 %	🟨 85.3 %
Code coverage	Function coverage	🟩 92.4 %	🟩 92.5 %
Code coverage	Line coverage	🟩 91.5 %	🟩 91.5 %
Lighthouse	Minimizes main-thread work	🟥 24.3 s	🟥 22.1 s
Lighthouse	Uses efficient cache policy on static assets	🟨 27 resources found	🟨 27 resources found
Lighthouse	Avoids enormous network payloads	🟩 Total size was 1,823 KiB	🟩 Total size was 1,821 KiB
Lighthouse	Max Potential First Input Delay	🟥 4,900 ms	🟥 3,400 ms
Lighthouse	Total Blocking Time	🟥 9,650 ms	🟥 8,280 ms
Lighthouse	JavaScript execution time	🟥 11.8 s	🟥 10.5 s
Lighthouse	Metrics	🟩 100%	🟩 100%
Lighthouse	Server Backend Latencies	🟩 150 ms	🟩 310 ms
Lighthouse	Initial server response time was short	🟩 Root document took 410 ms	🟩 Root document took 530 ms
Lighthouse	Eliminate render-blocking resources	🟥 Potential savings of 1,270 ms	🟥 Potential savings of 1,200 ms
Lighthouse	Network Round Trip Times	🟩 20 ms	🟩 60 ms
Lighthouse	Avoids an excessive DOM size	🟥 2,250 elements	🟥 2,246 elements

493 other audits are unchanged.

[BioPhoton]

Nice!! Left a small comment.

[matejchalk]

LGTM 👍

[BioPhoton]

Dope