PromQL: Simplify using decimals in PrometheusQueryTree

[vitlibar]

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Changelog entry (a user-readable short description of the changes that goes into CHANGELOG.md):

PromQL: Simplify storing ranges and offsets in PrometheusQueryTree,
use DateTime64 instead of DecimalField<DateTime64>.

Part of #89356

[clickhouse-gh]

Workflow [PR], commit [e48a4a3]

Summary: ❌

job_name	test_name	status	info	comment
Stress test (amd_debug)		failure
	Logical error: Block structure mismatch in A stream: different number of columns: (STID: 0993-38e6)	FAIL	cidb, issue	ISSUE EXISTS
Stress test (amd_tsan)		failure
	Logical error: Block structure mismatch in A stream: different number of columns: (STID: 0993-2da1)	FAIL	cidb, issue	ISSUE EXISTS
Stress test (amd_msan)		failure
	MemorySanitizer: use-of-uninitialized-value (STID: 3785-4c97)	FAIL	cidb, issue	ISSUE CREATED
AST fuzzer (amd_debug)		failure
	Logical error: Block structure mismatch in A stream: different number of columns: (STID: 0993-38e6)	FAIL	cidb, issue	ISSUE EXISTS
Performance Comparison (amd_release, master_head, 1/6)		failure
	Check Results	failure		IGNORED

[Copilot]

Pull request overview

This PR simplifies the handling of ranges and offsets in the Prometheus query parser by replacing DecimalField<DateTime64> and DecimalField<Decimal64> wrapper types with direct DateTime64 and Decimal64 primitive types throughout PrometheusQueryTree.

Changes:

• Replaced ScalarLiteral and IntervalLiteral nodes with a single Scalar node type
• Removed DecimalField wrappers in favor of storing DateTime64 and Decimal64 values directly
• Updated parsing utilities to work with the new type system and take a timestamp_scale parameter

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/TableFunctions/TableFunctionPrometheusQuery.cpp	Retrieves timestamp scale from storage metadata and passes it to the query parser
src/Storages/TimeSeries/PrometheusQueryToSQL.cpp	Refactored to use primitive decimal types instead of DecimalField wrappers, simplified arithmetic operations
src/Storages/StoragePrometheusQuery.cpp	Added whitespace formatting
src/Parsers/Prometheus/tests/gtest_PrometheusQueryTree.cpp	Updated test expectations to reflect renamed node types and simplified output format
src/Parsers/Prometheus/PrometheusQueryTree.h	Modified node structure to store primitive types and added timestamp_scale field to the tree
src/Parsers/Prometheus/PrometheusQueryTree.cpp	Updated node implementations to use primitive types and pass tree context for dumping
src/Parsers/Prometheus/PrometheusQueryParsingUtil.h	Restructured parsing API to separate scalar, timestamp, and duration parsing with explicit scale parameters
src/Parsers/Prometheus/PrometheusQueryParsingUtil.cpp	Implemented new parsing functions with proper overflow checking and scale handling
src/Parsers/Prometheus/PrometheusQueryParsingUtil-antlr.cpp	Updated ANTLR-based parser to use new parsing utilities and store values directly in nodes
src/Core/DecimalFunctions.h	Added tryMultiplyAdd helper function for overflow-safe decimal arithmetic

[vitlibar]

Ready for review