Support FIRST_VALUE and LAST_VALUE as aggregate functions, where possible, as synonyms for MAX_BY and MIN_BY

[lukaseder]

Numerous RBDMS support FIRST_VALUE and LAST_VALUE aggregate functions, e.g.:

• HANA https://help.sap.com/docs/SAP_HANA_PLATFORM/4fe29514fd584807ac9f2a04f6754767/034b17549b5d4b7d913e2c2770eea45b.html

They're kind of equivalent to the recently introduced MIN_BY and MAX_BY aggregate functions, though perhaps a bit more powerful, as the ORDER BY clause can be more complex?

• Add MAX_BY() and MIN_BY() aggregate functions #16071

To be investigated.

Tasks

• Add API support
• Add parser support
• Retrofit MIN_BY() and MAX_BY() implementation to use this API: Add MAX_BY() and MIN_BY() aggregate functions #16071