Feat: add terms enforcements for upcoming strategic changes

What does this MR do and why?

This MR closes #3622 by adding a new terms page for JiHu and replacing it with the upstream terms page.

Feat: add terms enforcements for upcoming strategic changes

• Add a new template to contain JH terms.
• Apply terms to sign-up page.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

FF on

Self manage

SaaS & Region HK

SaaS only

SaaS and submitting

FF off

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

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