Refactor: Simplify query evaluation and iterator handling

[tonyd3]

Query Engine Cleanup and Simplification

This pull request focuses on extensive code cleanup and simplification within the query evaluation engine. It removes redundant checks, consolidates iterator creation logic, and refines memory management across several core files. The changes aim to streamline the codebase, improve readability, and potentially offer minor performance gains by reducing unnecessary overhead.

Key Changes

• Consolidated iterator creation logic in NewUnionIterator and other factory functions, removing redundant checks for zero or single child iterators.
• Removed unused functions and dead code, including RangeNumber_Free, geoRangeLoad, checkResult, and populateRange.
• Renamed ContainsCtx to TrieCallbackCtx for improved clarity and consistency in callback contexts.
• Enhanced memory management in Redis_OpenReader by ensuring RSQueryTerm is freed regardless of iterator creation success.
• Refined the quickExit logic in UnionIterator to also apply when a query node's weight is zero, optimizing result collection for non-scoring sub-trees.
• Simplified error handling and control flow in various query evaluation functions, replacing goto statements with direct returns or RS_ASSERT where appropriate.

Affected Areas

• src/query.c (Query evaluation logic)
• src/geo_index.c (Geospatial indexing and filtering)
• src/redisearch_api.c (C API for RediSearch)
• src/profile.c (Query profiling output)
• src/iterators/union_iterator.c (Union iterator implementation)
• src/redis_index.c (Redis-backed index operations)
• src/query_internal.h (Internal query declarations)

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This summary was automatically generated by @propel-code-bot

[propel-code-bot]

[CriticalError]

Potential buffer overrun: the element is written before ensuring that the array has enough capacity. If ctx->nits == ctx->cap, the write on the previous line indexes one element past the allocated buffer. Re-allocate first, then assign:

Suggested change

	static void rangeItersAddIterator(TrieCallbackCtx *ctx, QueryIterator *it) {
	ctx->its[ctx->nits++] = it;
	if (ctx->nits == ctx->cap) {
	ctx->cap *= 2;
	ctx->its = rm_realloc(ctx->its, ctx->cap * sizeof(*ctx->its));
	}
	ctx->its[ctx->nits++] = it;

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