feat: add individual github, linkedin, portfolio website, and resume question types

[shannonaurl]

Reason

• support Portfolio unwrapping in the application by replacing Portfolio with its four question types (github, linkedIn, portfolio website, resume), so that each can be separately set to be required/optional on the application

Explanation

• added Github, LinkediN, Portfolio Website and Resume to the new question types to the QUESTION_TYPES/QUESTION_TYPES_UNIQUE
• updated HackerApplicationQuestionType to include new types

Other considerations

[github-actions]

Visit the preview URL for this PR (updated for commit b406098):

https://dev-nwplus-admin--pr128-36205849471-1nu2xe7f.web.app

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[geoff-jiang]

These four fixed questions are available in every section, but the portal saves their answers under the selected section. For example, GitHub in Basic Info writes basicInfo.github instead of skills.github (I see in your Portal PR these are meant to be in skills section only). Could we limit these types to Skills, or otherwise ensure they always save to the intended skills.* fields?