chore: skip gh CI checks when PR contains only docs and md files

[FollowTheFlo]

Added a GH action 'DetectChanges'
replaced all workflows that were using

paths-ignore:
      - '**.md'
      - 'docs/**'

by the new DetectChanges action.
It set RUN_CHECKS to true if PR only contains .md or docs/ files
This 'DetectChanges' action is now required to be true prior CI checks.

QA:

Tested with an epic branch (epic/CXSPA-12325) which has the same protection as develop.

• PR with only md files -> skipped check (CI -Check peerDepenedncies, SonarQube, Unite tests, static code checks)
• PR with pdf within spartacus/docs folder -> skipped checks
• Modified a .ts file, push to PR -> all checks running

[github-actions]

Merge Checks Failed

Please push a commit to re-trigger the build.
To push an empty commit you can use `git commit --allow-empty -m "Trigger Build"`

[cypress]

spartacus    Run #52629

Run Properties:   Passed #52629  •  4a60bca2ae ℹ️: Merge a4670b7e174c3d90b1d215e2ad332e097908c096 into a7279d9c65d23725b4aeff3929fc...

Project	spartacus
Branch Review	feature/CXSPA-12325
Run status	Passed #52629
Run duration	04m 22s
Commit	4a60bca2ae ℹ️: Merge a4670b7e174c3d90b1d215e2ad332e097908c096 into a7279d9c65d23725b4aeff3929fc...
Committer	Florent Letendre
View all properties for this run ↗︎

---

Test results
Failures	0
Flaky	4
Pending	0
Skipped	0
Passing	101
View all changes introduced in this branch ↗︎

[github-actions]

Merge Checks Failed

Please push a commit to re-trigger the build.
To push an empty commit you can use `git commit --allow-empty -m "Trigger Build"`