Clear terminal output of interactive screen on resize if alternate screen not in use

[dangooddd]

This PR is submitted to close #951.

Few moments about changes:

1. Interactive screen is always created with dimx = 0 and dimy = 0, so on first iteration of loop screen will be resized. In this situation we should not clear output of the screen.
   I add new variable validated_ that is true since second iteration.
   I think we can avoid this by passing component_ to the PreMain function to set init dimx and dimy, but than we should add component to the Install function, and than to the PostMain function... (will wait to implement this)
2. Some part of scrollback (no more than one terminal screen) will be cleared because of how I chose to implement this, but i do not think it is big problem

[dangooddd]

I think it works the way fzf does this. Results:

clear_on_resize.webm

[ArthurSonzogni]

Excellent! Thanks!

I approved % minor comments below: