feat: add standard schema support and associated tests

[GregoireBellon]

Description

This PR adds the support for standard schema, by copying their interface, extending the validator with it, and mapping class validator's "Validation Error" type to standard schema's "Issue".

I also wrote some tests, which are the same as the "nested validation" ones.

Since this function would be in the hot path, I tried to make it optimized, by avoiding recursion and preferring mutation to copy.

Supporting the Standard Schema interface is important, since it's blocking the adoption of it by NestJs (see related nestjs/nest/#14539)

edit: by itself, the PR in its current form would not be enough. We need to add a wrapper function, that takes a schema as input, and that outputs a validator containing the schema. Let me know if it sounds good to you.

Disclosure

I had to ignore the ESLint warning when copying the standard schema interface.

Checklist

• the pull request title describes what this PR does (not a vague title like Update index.md)
• the pull request targets the default branch of the repository (develop)
• the code follows the established code style of the repository
  • npm run prettier:check passes
  • npm run lint:check passes
• tests are added for the changes I made (if any source code was modified)
• documentation added or updated
• I have run the project locally and verified that there are no errors

Fixes

addresses #2577

[0x0bit]

@braaar @NoNameProvided

[niemyjski]

Is this type correct?

[niemyjski]

@braaar @NoNameProvided This would be massive if this can be supported. See discussion here nestjs/nest#14539 for possible rework?