Adds the basic structure for the Sound library, and populates it with the first couple (not yet implemented) methods.

Implemented Sound.PlayClick and manually verified that it works!

Adds the documentation for PlayClick.

Adds the strings for the rest of the Sound APIs, as copied from SmallBasic.Web\Content\js\json\generated-output.json

Copy better strings into Sound.Play and Sound.Play.FilePath, per the actual documentation headers in the original code.

Implement the structure of the rest of the Sound APIs, + actually implement the three easy ones (playing sound files like what was already implemented for Click)

Refactor the Sound library to make it more unit testable, and add some basic tests.