Do not cmp presorted meta DB values in SearchV2

[cthulhu-rider]

Is your feature request related to a problem? Please describe.

iterator can collect values either pre-sorted or not. Currently, iterator always checks candidate against optional cursor and the accumulated ones. This should be done only for:

• != <any> and PREFIX int filters collected from two key spaces
• ??? (revise all cases accurately)

cmp'ing for ordered iterator adds CPU overhead, thereby slowing down execution. Although, given the limits, these are not high expenses, they should still be avoided

Describe the solution you'd like

precalc flag whether iterator goes over presorted values, and make cmp only otherwise

Additional context

• Implement searchv2 #3058