use `(col >= 'val') and (col < 'val'+maxChar4StartsWith)` for startsWith
new database configuration parameter maxChar4StartsWith
(default is 'џ' a Cyrillic Small Letter Dzhe. U+045F).
If parameter is not empty (by default), UBQL with .where('col', 'startsWith', 'val')
condition will be transformed into
(col >= 'val') and (col < 'val'+maxChar4StartsWith)
instead of col like 'val%'