[NT-1269, NT-1270] Deprecate BackingViewController

[justinswart]

📲 What

• Deprecates all old references to BackingViewController, which is now replaced by ManagePledgeViewController.
• Allows a creator to view a backing from a message thread via the dashboard.

🤔 Why

BackingViewController was still left over from the work that we did to re-build our checkout flow natively. This PR removes it and updates the callsites that configured and presented it.

🛠 How

• Refactored ManagePledgeViewController to support only being configured by a Project param (slug or id) and a Backing param (id).
  • ManagePledgeViewModel will now always fetch the relevant Project and Backing instead of only sometimes fetching the Project as before. This just helped to simplify this view model as it was becoming unwieldy trying to handle all of the configuration scenarios.
• Updated callsites and configuration in the following view controllers:
  • ActivitiesViewController.
  • MessagesViewController.
  • ProjectActivitiesViewController.
  • ProjectPamphletContentViewController.
  • ProjectPamphletViewController.
• Updated MessagesViewModel to retrieve the backing ID from the MessageThread.
  • Note: I wasn't able to find a scenario in which the MessageThread did not have a Backing (unless the thread was between a creator and a user that hadn't backed of course). I would just want to be sure there isn't a use case that I'm unaware of in which the thread might not have a Backing.

👀 See

Before 🐛	After 🦋

✅ Acceptance criteria

• Test navigating to manage/view a backing from ActivitiesViewController.
• Test navigating to manage/view a backing from MessagesViewController.
  • This is accessible via the dashboard logged in as a creator that has a message thread with a backer.
• Test navigating to manage/view a backing from ProjectActivitiesViewController.
• Test navigating to manage/view a backing from ProjectPamphletContentViewController.
• Test navigating to manage/view a backing from ProjectPamphletViewController.

[nativeksr]

	1 Warning
⚠️	Big PR

Generated by 🚫 Danger

[ifbarrera]

We also have this function in SharedFunctions.swift:

/**
 Returns a reward from a backing in a given project

 - parameter backing: A backing
 - parameter project: A project

 - returns: A reward
 */

internal func reward(from backing: Backing, inProject project: Project) -> Reward {
  let noRewardFromProject = project.rewards.first { $0.id == Reward.noReward.id }

  return backing.reward
    ?? project.rewards.first { $0.id == backing.rewardId }
    ?? noRewardFromProject
    ?? Reward.noReward
}

Seems pretty much identical, is it worthwhile to consolidate so we don't have to maintain this logic in two places?

[ifbarrera]

You could use the shared function func currentUserIsCreator(of project: Project) here 😅

It's in... you guess it, SharedFunctions.swift

[ifbarrera]

Could also do filterMap here so you don't need to add the skipsNil()

[ifbarrera]

Looks good! Just one logging line that needs to get removed 😄

[ifbarrera]

Log here 😄