Create strategy for caching improvements

[mosabua]

In a number of contributor meetings a desire to cache various aspects has come up repeatedly. Following are a number of ideas and thoughts to drive the conversation:

• Caching cut be initiated and managed on Trino cluster (coordinator) but also on Trino Gateway in front of multiple clusters, both approaches could also be combined.
• There are lots of choices for caching backends, each with different pros and cons
• Access control permissions must be taken into account, but limit impact of cache, potentially ignore for metadata or make configurable?

A number of different aspects can be considered for caching:

• Metadata caching - potentially has huge impact since many client tools are very demanding about metadata
• Result set caching
• Fragment caching (partial result set)

[mosabua]

This will need further meetings and discussions to move forward.