Add Javascript-like array methods to TArrayUtils

[delphidabbler]

In a comment on issue #8 it was suggested that it maybe a good idea to add some JavaScript-style array methods to TArrayUtils, specifically forEach(), some(), all()every() & map(). To those we can add reduce() (& reduceRight()?).

In this comment on issue #40 implementations were proposed for TArrayUtils' Some<T>() and Every<T>().

[delphidabbler]

The JavaScript array methods are documented here.

[delphidabbler]

I've been adding lots of methods to TArrayUtils on my local machine. So many that the thing is getting a bit too big for a code snippet.

So I'm thinking it would probably be better to leave the TArrayUtils snippet as-is and to move the expanded code into a new repo within the DelphiDabbler Code Library.