OR-5281 Error handling :: Dealing with failure

[crazymanish]

Context

• Close ticket: [w30(23july-29july)] Error Handling: Dealing with failure #44

In this PR

• All try* operators
• The try-prefixed operators let you throw errors from within them, while non-try operators do not.
• All try-prefixed operators in Combine behave the same way when it comes to errors.
• Example: tryMap, tryFirst, tryLast etc

---

• mapError(_:) Converts any failure from the upstream publisher into a new error.
• https://developer.apple.com/documentation/combine/fail/maperror(_:)/

---

• replaceError(with:) Replaces any errors in the stream with the provided element.
• If the upstream publisher fails with an error, this publisher emits the provided element, then finishes normally.
• This replaceError(with:) functionality is useful when you want to handle an error by sending a single replacement element and end the stream.
• https://developer.apple.com/documentation/combine/deferred/replaceerror(with:)/