Support min_by in Aggregation function

[Weijun-H]

Is your feature request related to a problem or challenge?

Description	Finds the row with the minimum val. Calculates the arg expression at that row. This function is affected by ordering.
Example	min_by(A, B)
Alias(es)	argMin(arg, val), arg_min(arg, val)

Describe the solution you'd like

D SELECT min_by(x, y) FROM VALUES ('a', 10), ('b', 50), ('c', 20) AS tab(x, y);
┌──────────────┐
│ min_by(x, y) │
│   varchar    │
├──────────────┤
│ a            │
└──────────────┘

Describe alternatives you've considered

No response

Additional context

https://duckdb.org/docs/sql/functions/aggregates#min_byarg-val
https://docs.databricks.com/en/sql/language-manual/functions/min_by.html

[dharanad]

take

[korowa]

These probably could be an aliases (with some additional transformations) for first/last aggregation functions -- otherwise there it'll end with two implementations of basically the same function (not something bad, but still redundant).

Relevant discussion -- #12075

[Lordworms]

Also implemented in #12284 using a function rewrite way

[alamb]

Given #12357 we may want to move this function to some other repo rather than the core

[alamb]

Suggestion: #12254 (comment)

[alamb]

We are going to implement these in a different repository so closing this ticket to avoid confusion: #12254 (comment)