Add play from functionality and ability to manipulate the AudioVizualizerView with touches via move() method

[t0a0]

I used Bogdan's pull request and modified it, since it was buggy.

Changes:

• Replaced AudioVizualizationView's play(for:) method to play(from: totalDuration:) with the default from value set to 0.
• Introduced resume() method, which is supposed to be used only after pause() method.
• Introduced move(to: fromTotalDuration:) method to be able to adjust the current gradient position (can be used both when playing and paused). Other changes:
  • Added microphone usage description into example so the app doesn't crash on the start
  • Fixed chronometer method start(shouldFire:) ignoring the shouldFire argument.

[t0a0]

I also added touches Delegate, so now the user can manipulate the AudioVizualizerView and added an example usage to the view controller. You can click at any point of the view and the playback will start from there. However, the sound playback only works for the first time you start playing from a certain time, sorry, I didnt have time to tweak the example, however the visualization works perfectly fine

[t0a0]

ill submit another PR when everything is done