getSharedState() will not return the latest if the given event is nil

[yangyansong-adbe]

Expected Behaviour

    /// Retrieves the `SharedState` for a specific extension
    /// - Parameters:
    ///   - extensionName: An extension name whose `SharedState` will be returned
    ///   - event: If not nil, will retrieve the `SharedState` that corresponds with this event's version. If nil will return the latest `SharedState`
    ///   - barrier: If true, the `EventHub` will only return `.set` if `extensionName` has moved past `event`
    ///   - sharedStateType: The type of shared state to be read from, if not provided defaults to `.standard`
    /// - Returns: The `SharedState` data and status for the extension with `extensionName`

From the above public API doc, getSharedState() should return the latest SharedState if the given even is nil.

Actual Behaviour

aepsdk-core-ios/AEPCore/Sources/eventhub/EventHub.swift

Line 233 in 9fe6554

let result = sharedState.resolve(version: version)

SharedState.resolve() will return the oldest one if the event version is 0.

Reproduce Scenario (including but not limited to)

Steps to Reproduce

Platform and Version

Sample Code that illustrates the problem

Logs taken while reproducing problem

[nporter-adbe]

Are we sure we want to make this change and not update the doc comment?
#299

[nporter-adbe]

Talked with @shalehaha the current implementation is desired, however, somehow the doc comment got out of sync. To resolve this issue I think we just need to update the doc comment.

https://github.com/adobe/aepsdk-core-ios/pull/299/files#diff-02bd1581c751b39213c003d305212478496f8a5290a1a877cef358a338c892f4R187