feat: Naver Auth Provider

[esinx]

What kind of change does this PR introduce?

This PR adds Kakao(https://naver.com/) as an external provider.

What is the current behavior?

This provider did not exist before.

What is the new behavior?

Based on Naver developer docs(https://developers.naver.com/docs/login/api/api.md), this PR creates a provider & test suite for Naver external provider.

Additional context

This was mentioned before #1251, but the PR was closed due to inactivity.
Someone asked for this during supabase launch week 15 @ seoul 😄

[coveralls]

Pull Request Test Coverage Report for Build 16663254924

Details

• 59 of 65 (90.77%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.08%) to 70.627%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/api/provider/naver.go	56	62	90.32%

Totals
Change from base Build 16618040645:	0.08%
Covered Lines:	11912
Relevant Lines:	16866

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💛 - Coveralls

[hf]

We don't have anyone speaking Korean in the team, making fixes to this in the future hard. We'd like to support this via generic OAuth provider support which is currently being planned and high on the roadmap.