Enhance MergeRangeFilterOptimizer to rewrite predicate A < 10 OR A = 10

Currently, MergeRangeFilterOptimizer don't support operations to optimize query with filter patterns consisting of predicate A < 10 OR A = 10 as A<=10. this issue will track removal of that limitation and provide support for the same as part for optimizing query execution

Locate MergeRangeFilterOptimizer and read its existing handling of range predicates. Verify how the optimizer represents A < 10 OR A = 10, then add support for rewriting that pattern as A <= 10 and confirm the optimized query behavior with the relevant optimizer tests.

Written by the indexing model from the issue text.