feat(flag): add a help flag for the feature command

[C0ZEN]

PR Checklist

Please check if your PR fulfils the following requirements:

• The commit message follows our guidelines
• Tests for the changes have been added/updated (for bugfix/feature)
• Docs have been added/updated (for bugfix/feature)

PR Type

What kind of change does this PR introduce?

• Feature (a new feature)
• Bugfix (a bug fix)
• Style (changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc))
• Refactor (a code change that neither fixes a bug nor adds a feature)
• Perf (a code change that improves performance)
• Test (adding missing tests or correcting existing tests)
• Build (changes that affect the build system, CI configuration or external dependencies)
• Docs (changes that affect the documentation)
• Chore (anything else), please describe:

What is the new behaviour?

• Include a new field when showing the "Empty feature name" to help users to use the --help flag
• Include a new field when showing the "Wrong feature name" to help users to use the --help flag
• Add a class to handle easily all the flags with their constraints (duplicate, opposite, etc)
• Add the logic to detect either or not a flag was specified before the feature name
• Add the logic to process the flags and execute the related actions

Does this PR introduce a breaking change?

• Yes
• No

Other information

Closes #735

[codecov]

Codecov Report

Merging #1538 (3cabff8) into develop (666d6c9) will increase coverage by 0.00%.
The diff coverage is 100.00%.

❗ Current head 3cabff8 differs from pull request most recent head cc4c812. Consider uploading reports for the commit cc4c812 to get more accurate results

@@           Coverage Diff            @@
##           develop    #1538   +/-   ##
========================================
  Coverage    97.33%   97.34%           
========================================
  Files          351      351           
  Lines         7931     7949   +18     
  Branches       795      783   -12     
========================================
+ Hits          7720     7738   +18     
  Misses         211      211           

Flag	Coverage Δ
integration	97.34% <100.00%> (+<0.01%)	⬆️

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Impacted Files	Coverage Δ
...ommand-feature-empty-feature-name-error.service.ts	100.00% <100.00%> (ø)
...ommand-feature-wrong-feature-name-error.service.ts	100.00% <100.00%> (ø)