Rewrite most aggregations as annotated functions

[dain]

Description

NOTE: This is based on #11476, so skip the first few commits that overlap

Convert all of our aggregations to annotated functions (except for reduce which uses lambdas). To do this I extended the annotation system with:

• Add generic state variables, so a single function can be used for any type regardless of stack type
• In-out calling convention so generic state variables can be used in operators like equals, hashcode, and comparison
• Add support for injection into state factories and serializers, so they can access types and operators
• Add support for multiple state variables in annotated aggregate functions

Related issues, pull requests, and links

Documentation

(x) No documentation is needed.
( ) Sufficient documentation is included in this PR.
( ) Documentation PR is available with #prnumber.
( ) Documentation issue #issuenumber is filed, and can be handled later.

Release notes

I'm not sure how much of this is visible to the SPI yet.

( ) No release notes entries required.
( ) Release notes entries required with the following suggested text:

# Section
* Fix some things. ({issue}`issuenumber`)

[sopel39]

cc @radek-starburst @lukasz-stec @skrzypo987

[electrum]

Commits through "Convert qdigest_agg and merge aggregations to annotated functions" look good

[electrum]

Commits through "Convert avg(REAL) aggregation to annotated function" look good

[ksobolew]

Challenge accepted ;)

Suggested change

	Optional<Class<?>> nativeContainerType = Arrays.stream(annotations)
	.filter(SqlType.class::isInstance)
	.map(SqlType.class::cast)
	.findFirst()
	.map(SqlType::nativeContainerType);
	// Note: this cannot be done as a chain due to strange generic type mismatches
	if (nativeContainerType.isPresent() && !nativeContainerType.get().equals(Object.class)) {
	parameterType = nativeContainerType.get();
	}
	parameterType = Arrays.stream(annotations)
	.filter(SqlType.class::isInstance)
	.map(SqlType.class::cast)
	.findFirst()
	.<Class<?>>map(SqlType::nativeContainerType)
	.filter(not(Object.class::equals))
	.orElse(parameterType);

[sopel39]

@dain this does not split aggregation stats into smaller states, right? Hence there shouldn't be perf difference?

[przemekak]

Here is the report with comparison before and after this change, looks like result are stable without any regressions (maybe even slightly better).
Aggregations refactor comparison.pdf