OR-5261 Combining Operators:: merge(with:)

[crazymanish]

Context

• Close ticket: [w23(4june-10june)] Operators:: Combining Operators: Combining #24

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

• Combining Operators:: merge(with:)
• merge(with:) Combines elements from this publisher with those from another publisher of the same type, delivering an interleaved sequence of elements.
• https://developer.apple.com/documentation/combine/publishers/reduce/merge(with:)
• This operator interleaves emissions from different publishers of the same type.