Tailor DateTime scalar filter to the domain of time

[jasonkuhrt]

Currently we have:

input DateTimeFilter {
  equals: DateTime
  gt: DateTime
  gte: DateTime
  in: [DateTime!]
  lt: DateTime
  lte: DateTime
  not: DateTime
  notIn: [DateTime!]
}

This just an IntFilter using DateTime scalar type. I think we should filter tailored to the domain of time.

[jasonkuhrt]

May be desirable to push upstream into Photon.

Proposal:

input DateTimeFilter {
  at: DateTime
  before: DateTime
  beforeOrAt: DateTime
  after: DateTime
  afterOrAt: DateTime
  within: [DateTime!]! # domain-friendly short hand for specifying a before & after
  notWithin: [DateTime!]!
}

Loses some power but for the domain of time seems fine and now its simpler + clearer.

CC @Weakky do you think this is a better default API for GQL clients?

I'm not sure, tbh

[Weakky]

While I like it, I'm wondering whether the change is worth the lack of consistency with all other filter types (String/Int/Float/BooleanFilter)

[jasonkuhrt]

Feels like something that should be possible via customization/naming strategy. We can reference this issue as a use-case/example when we tackle that. Not only does my example show name strategy change, but also actual field changes (some ones added, some ones removed).