Added a macro which chains transformations on collections.

[ghost]

Chaining multiple operations on collections looked like a common task. That's why I added it to base library.

[jpsamaroo]

I'm not sure if this functionality is desired in Base or Stdlib (maybe I'm missing some pre-existing discussion about this), but if it is, you should:

• Add tests
• Update NEWS.md
• Provide a few motivating examples of where one could use @chain to great benefit over alternatives

[JeffBezanson]

Welcome, @sagartewari01, thanks for making a PR.

See e.g. #5571 (comment) for several alternate designs of things like this that have been proposed. I don't think we're ready/willing to commit to adding something like this to Base.

@jpsamaroo is right that we require tests, but it can be OK to make a proposal without writing detailed tests until design discussion is complete.

[ghost]

@JeffBezanson Thanks a lot, the thread was informative.