Optimize route book rendering performance

[TalDerei]

A consequence of increasing the DEX engine’s execution budget from 128 to 4K is degrading the performance of the simulate RPC, which as a side-effect slows down route book rendering. The route book doesn't go through pindexer. This is protocol-related rather than veil-specific, and will require changes to the simulation RPC logic. We also discussed implementing an in-memory cache of SQL queries and a Redis sidecar to improve node querying performance. Currently, route book takes 30s+ to load on prod site.

That said, there may still be some inefficient fetching patterns on the Veil side that represent low-hanging fruit for potential optimization.

[TalDerei]

opened for tracking, optimistically assigning to @erwanor @cronokirby