SpriteBatch improvements

This is rewrited version of https://github.com/mono/MonoGame/pull/3290.
Without any formatting and regions.

 PS. Parameters is now named like in XNA.
This could probably be better.  Maybe something like:
```
Helper for drawing text strings and sprites in one or more optimized batches.
```
This is also a good case where more detailed remarks and maybe a simple usage example would be nice.