Support for "last" measure with preaggs

**Is your feature request related to a problem? Please describe.**
I have a schema where I want to select the last value, base on the timestamp, for a given dimension. I currently use (with presto as db):

last: {
sql: `max_by(value, ${CUBE}.timestamp)`,
type: `number`
},

which works well except that it doesn't match to any preaggs.

**Describe the solution you'd like**
I was wondering if it would be possible to include `first` and `last` as builtin measure types to allow them to work with preaggs

**Describe alternatives you've considered**
Not sure if there are any other ways to get this to work with rollups, can't find any docs on rollups + number measure type

**Additional context**
trying to build a realtime view