refactor joins to use direct implementation or each type rather than composition of inner+anti joins

.changeset/fast-joins-redesign.md

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+---
+"@tanstack/db-ivm": patch
+---
+
+Redesign of the join operators with direct algorithms for major performance improvements by replacing composition-based joins (inner+anti) with implementation using mass tracking. Delivers significant performance gains while maintaining full correctness for all join types (inner, left, right, full, anti).

.changeset/odd-mangos-pick.md

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+---
+"@tanstack/db-ivm": patch
+---
+
+Change the ivm indexes to use a three level `key->prefix->hash->value` structure, only falling back to structural hashing when there are multiple values for a single prefix. This removes all hashing during the initial run of a query delivering a 2-3x speedup.