add filters for SPM baseline capture functionality

[eurekaka]

Development Task

Currently, if tidb_capture_plan_baselines is enabled, SPM would capture SQL patterns which occur more than once and build a baseline binding for it if there doesn't exist one. This would be annoying if users enable this feature in product environment, because there may be huge amount of bindings built.

We can let users define filter / rules to constraint the capture behavior, e.g, only capture baselines for specified tables, or specified connection.