start pr for textrendering in idxviewer

Слиты nikitronn запросил слияние b28_idxview_wtext в b28_prelease_master

Created by: zeffii

adresses longstanding regression in idxviewer - unable to draw arbitrary strings on vertex locations.

  • allow text input
  • auto repeat, in a meaningful way

"background" feature will not be implemented in this PR.