Cursor movement should be logical, not visual

First attexmp to fix #165397. The main problem inside KateView is that
all the methods were thinking in visual mode. In RTL more the logic gets
reversed.

What this his fix does:
 - KateViewInternal: s/cursorLeft/cursorPrevChar/ and similar methods
 - KateView: depending on the direction of the paragraph, when
   "left/right" arrows are pressed, choose cursorPrevChar() or
   cursorNextChar()
 - Small fix inside KateViInputModeManager due the above fixes.

What needs to be done:
 - Text aliengment is wrong. wrong. wrong.
 - One should have the ability to choose the text alignment manually.
 - If you start in an LTR paragraph, the next paragraph is RTL and
   you press "right" you will get stucked between those two lines.
   See the above logic to understand why.
   Solution:
   the next/prev chat methods should depend not on the current
   paragraph, but the paragraph that originated the keyboard press.