Is your feature request related to a problem? Please describe.
Because of escaping characters on the key, I can't able to add brackets in key without having escaped characters.

Describe the solution you'd like
I'm suggesting to have a additional way to override the key replacers same as with the value.

to have something like this definition

Cookies.withConverter({
  write: function (value, name) {
    return String(value).toUpperCase()
  }
})

and in additional, this definition to have an overloaded return type to keep both definition exist.

Cookies.withConverter({
  write: function(value, key) {
    return {
      key: String(key),
      value: String(value).toUpperCase()
    }
  }
})

Describe alternatives you've considered
Passing additional optional parameter to disable escapers.

Cookies.set('name', 'value', {
  unescapedName: true,
  unescapedValue: true,
  //...
});

Additional context
I know this solution can expect this this answer #590 (comment) . I'm only suggesting to have an optional way to avoid complying to standards.

Such as this