feat: support metadata in pipe

[xcfox]

Implements #373, support metadata in pipe and pipeAsync.

In this implementation, metadata is used as previously discussed

// With the new `pipe` function
const UserSchema = pipe(
  object({
    id: pipe(string(), uuid(), primaryKey()),
    name: pipe(string(), maxLength(32), unique()),
    bio: pipe(string(), description('Text ...')),
  }),
  table('users')
);

Metadata can add extra properties on the schema:

const schema = pipe(
  object({
      key: string(),
  }),
  withDescription('some Description')
)
console.log(schema.description) // 'some Description'

Currently, I've added two metadata:

• withDescription: add description for schema
• asParser: add a parse method for schema

[fabian-hiller]

Sorry for not getting back to you in #373, but I am still working on other areas of the library as a result of our rewrite, and the metadata feature is not something I want to rush. It is important to me to make the right decisions. As soon as I find the time, I will answer you in the issue.