OR-5256 FilteringOperators:: filter(_:) tryFilter(_:)

[crazymanish]

Context

• Close ticket: [w21(21may-27may)] Operators:: Filtering Operators: Compacting and ignoring #19

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

• FilteringOperators:: filter(_:) tryFilter(_:)
• filter(_:) Republishes all elements that match a provided closure.
• https://developer.apple.com/documentation/combine/publishers/collect/filter(_:)
• tryFilter(_:) Republishes all elements that match a provided error-throwing closure.
• https://developer.apple.com/documentation/combine/publishers/collect/tryfilter(_:)