OR-5252 TransformingOperators:: Map

[crazymanish]

Context

• Close ticket: [w20(14may-20may)] Operators:: Transforming Operators: Mapping values #15

Operators are publishers

• In Combine, methods that perform an operation on values coming from a publisher are called operators.
• Each Combine operator actually returns a publisher. Generally speaking, that publisher receives the upstream values, manipulates the data, and then sends that data downstream.

In this PR

• TransformingOperators:: Map
• map Transforms all elements from the upstream publisher with a provided closure.
• https://developer.apple.com/documentation/combine/publishers/collect/map(_:)-8fi4q