feat: add case-insensitive support in advanced Json filtering

[lubosmato]

The PR adds case field into Json filtering to allow case-insensitive text filtering with Json fields.

E.g.:

prisma.article.findMany({
  where: {
    title: {
      path: ["en"],
      string_contains: searchText,
      mode: "insensitive",
    },
  }
})

Fixes https://github.com/prisma/prisma/issues/7390