Don't persist following

[zeitschlag]

tl;dr: Don't use MastodonUser on "Following"-screen, but Mastodon.Entity.Account

This PR does several things:

• Add MBProgressHUD (cause I'm lazy) to show loading-states
• It fetches the accounts that an account follows and the relationships
• It improves the Loading-state of the FollowButton in UserView
• Speaking of which: The FollowButton uses configuration now (which makes showing an ActivityIndicator very easy). Oh, the FollowButton is gone and got replaced by a basic UIButton.
• It migrates Kanna from Pods to SPM (We could think about removing Cocoapods, we now only use it for tooling aka SwiftGen and Sourcery and those are available via homebrew etc., too)

[kimar]

When trying to view the followers of any account in my timeline, I'm only seeing an infinite spinner but no results. Looking at my own followers (Account Tab) works.

This might be related to the fact that, we're not showing following people which are on another server than the currently logged in instance. (In the current prod version I'm seeing the message in the screenshot instead).

Also I'm seeing lots of JSON decoding errors when going back to my Timeline (Mastodon Server v4.2.1):

Swift.DecodingError.keyNotFound(CodingKeys(stringValue: "id", intValue: nil), Swift.DecodingError.Context(codingPath: [], debugDescription: "No value associated with key CodingKeys(stringValue: \"id\", intValue: nil) (\"id\").", underlyingError: nil))

and

Swift.DecodingError.typeMismatch(Swift.Array<Any>, Swift.DecodingError.Context(codingPath: [], debugDescription: "Expected to decode Array<Any> but found a dictionary instead.", underlyingError: nil))

[kimar]

I've used MBProgressHUD in the past as well but I'm not a huge fan of pulling in a dependency which hasn't been updated in years, but also I totally feel the pain of not wanting to write an indicator from scratch.

@zeitschlag what do you think of creating a light-weight wrapper around UIAlertController to server as a modal loading indicator?

[zeitschlag]

@kimar Thank you for your review :) Regarding MBProgressHUD: I'm not a huge fan of pulling in dependencies (regardless of their age) either, but in this case, I'd consider it a pragmatic way:

• It does basic stuff, nothing critical. So in case, it might stop working (to me, MBProgressHUD has proven to be a reliable library for years), we know how to easily replace it (create a light-weith wrapper that does the same thing and handle presentation).
• It hasn't been updated in three years, yes, but I'd consider it more due to a "It does its thing good enough" than "Noone wants to take care of it"
• I wanted to focus on the task at hand (migrating the following-list to entities and building endless loops :D) than adding a new, fancy feature.

We can still replace it with something better/nicer/... at any time, I'd have nothing against it and I'd encourage you (or everybody else reading this) to suggest/build something better/nicer/... :)

[zeitschlag]

Regarding the DecodingErrors: It's probably connected to 02207d1. I'll have a look at them. Also I'll also check the slighty higher memory usage. I didn't notice that before, could be connected to the images?

The reason for the DecodingErrors were issues with domains. On my machine, it works now™️

[kimar]

Tested and LGTM 🚀 Looks solid to me now.