feat: implement forgot password feature

[xielong]

Description

Implement forgot password feature.

Fixes #5307

Type of Change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update, included: Dify Document
• Improvement, including but not limited to code refactoring, performance optimization, and UI/UX improvement
• Dependency upgrade

How Has This Been Tested?

Here are some feature screenshots:

Suggested Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods
• optional I have made corresponding changes to the documentation
• optional I have added tests that prove my fix is effective or that my feature works
• optional New and existing unit tests pass locally with my changes

[xielong]

Todo List

Frontend: Add a reset password link on the login page, create a reset password page
Reset Password Emails: Request email, success notification email
Reset Password Logic: Generate token, set expiration time, security checks, update password
Multilingual Support: Add multilingual support, translate all pages and email templates

[takatost]

Hey @crazywoola, could you help set up a connection? It'd be great if we can align better by chatting with our product manager and designer.

[crazywoola]

FE LGTM

[takatost]

Nice job! 👍 Got a couple of suggestions:

1. On the login page, if the "Forgot Password" link is sent twice, both reset links can be used. It should only allow the last one to be usable.
2. If possible, add a rate limit so that password resets can only be requested a certain number of times within an hour to prevent email spam.

[takatost]

Thanks!!