Calcite integration. IndexCondition refactoring

Currently IndexCondition is quite cumbersome and hard to understand. The difference between bounds and conditions is unclear as well as unclear what should be used to estimate a selectivity and what should be used to estimate a self cost.

Thus I suggest to change it in a follow way:

• remove [lower|upper]Cond
• bounds remains as is
• self cost estimation of an AbstractIndex should be calculated with regard to bounds
• selectivity should be calculated with regards to whole condition that is member of ProjectableFilterableTableScan