Feature: support more kinds of statistics information

[leiysky]

We need more statistical information to provide a more precise cost estimation of plans.

• Number of distinct values(NDV), used to estimate cardinality, high priority #8046
• Histogram of values, used to estimate cardinality, medium priority
• Multi-column histogram, used to detect the correlation between columns, low priority
• Cross table histogram, used to detect the correlation between tables, low priority

[leiysky]

cc @dantengsky