added fastscroll functionality and some layout changes inside the note view

[HM201]

I added a fastscrollscrollview in the notes layout upon request on issue #523
I made some layout changes in the notes layout based on user request on issue #434

[federicoiosue]

Hi Misham,

thanks for your contribution. However there are some problems to be solved before merging your pull request:

1. Your code misses both UI and unit testing.

2. The first reason of missing tests is that the code has been took from this library so I'm asking: why copying code (that would also increase technical debt of Omni Notes) instead of using that as external library? Yes that library does not contains tests neither but eventual changes or fixes made to it would have been easier to include into ON later.

3. The fastscroll code/layout modification causes a problem with the position of the scrollbar itself, as shown into this screenshot
   

4. The note's detail space layout modification causes the following whenever a note is going to be modified, except than when is is long enough to be scrolled vertically

Great work for now, I've tried and this change really seems useful!