Refactor gulpfile to be more dynamic

[wordpressfan]

Closes #6601

Here I restructured the the gulp tasks and split main tasks between css and js tasks and has a config file to define the gulp tasks and the corresponding method to do that task.

List of gulp tasks that can be called directly using gulp cli command are mentioned here:

https://github.com/wp-media/wp-rocket/blob/a8e8fead41e3103511a467bffaf634cdf3f75a9c/src/js/gulp/gulpconfig.js

Also I added main big scripts inside package.json

Q: Do we need to be backward compatible with the old gulp tasks that I removed in this PR?

[codacy-production]

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Coverage variation	Diff coverage
Report missing for 2b088a31	✅ ∅ (target: 50.00%)

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (2b088a3)	Report Missing	Report Missing	Report Missing
Head commit (a14896b)	37185	14389	38.70%

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#6625)	0	0	∅ (not applicable)

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

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[MathieuLamiot]

Should this PR be made a real PR and not a draft? As I see it's "Ready for review". Thanks!

[Khadreal]

gulp build:sass:all task did not complete every other tasks is fine.

cc @wordpressfan

[wordpressfan]

gulp build:sass:all task did not complete every other tasks is fine.

cc @wordpressfan

Done

[remyperona]

Could you add somewhere (either in the main gulp file, or the readme) The list of all gulp commands, and what it does? That would be helpful for everyone old and new as a quick reference instead of having to inside the code.

[wordpressfan]

Could you add somewhere (either in the main gulp file, or the readme) The list of all gulp commands, and what it does? That would be helpful for everyone old and new as a quick reference instead of having to inside the code.

Good idea, doing that now.

[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
Report missing for 2b088a31	✅ ∅ (target: 50.00%)

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (2b088a3)	Report Missing	Report Missing	Report Missing
Head commit (51ef5a1)	37185	14389	38.70%

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#6625)	0	0	∅ (not applicable)

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

See your quality gate settings    Change summary preferences

_{Codacy will stop sending the deprecated coverage status from June 5th, 2024. Learn more}

Footnotes

1. Codacy didn't receive coverage data for the commit, or there was an error processing the received data. Check your integration for errors and validate that your coverage setup is correct. ↩