[Epic] FSSTView in LiquidCache

[XiangpengHao]

I'm cooking some new string representation that can potentially increase many query's performance by orders of magnitude.

Design doc can be find here: https://github.com/XiangpengHao/liquid-cache/blob/main/dev/design/00-fsst-view.md

#297 has implemented most of the logic, #299 has added benchmark to show that it performs particularly well for predicates that can leverage string prefixes, e.g., eq, neq, lt, gt, etc.

Remaining work are:

1. Make it the default string representation in LiquidCache. This requires some more rigorous testings and benchmarking to understand the trade-offs, especially that we need a bit more memory compare to the existing approach.
2. Implement the disk eviction. The idea is to keep the prefix part in memory, and evict the fsst buffer to disk. And later use some FAST IO to read the fsst on-demand.