* Grammar for ES|QL change point (with dummy impl)

* pipeline breaker

* ChangePointOperator

* Add sorting

* basic csv test

* conflict

* Update docs/changelog/120998.yaml

* [CI] Auto commit changes from spotless

* polish

* Non-long data type

* Move OrderBy/Limit to the logical plan

* fix mem.leak

* csv test for reusing column names

* Warning indeterminable

* capability

* handle null values

* too much data

* type text->keyword

* default timestamp and output columns

* spotless

* ChangePointOperatorTests + fix memory leaks

* [CI] Auto commit changes from spotless

* improve test

* add comments/todos

* handle multivalued columns

* don't register unserialiazable

* surrogate

* make "too much data" tests readable

* more tests

* Error handling

* fix multivalued test

* more name conflict tests

* [CI] Auto commit changes from spotless

* more tests

* improve code

* CSV test for various input key/value types

* one more csv test

* Check sortable/numeric for all types

* add null type to testChangePoint_valueNumeric

* more CSV tests

* skip nulls instead of zeroing them

* error on MV

* Test+todo for nicer error message

* better error msg

* Revert "better error msg"

This reverts commit 21ec77c.

* fix

* make csv test deterministic

* replace NamedExpression -> Attribute

* skip MVs + warning

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Co-authored-by: elasticsearchmachine <[email protected]>