Secure Settings store (#831)

* Add SettingsStore

* Use keychain instead of UserDefaults in JustUpdatedChecker.swift

* Add ability disable the SSH comment via settings

* Make SettingsStore functions non-static, re-implement them as
subscripts and make settingsStore an environmentObject

Fixes: https://github.com/maxgoedjen/secretive/pull/536#discussion_r1508446459

* Add rawValues for CommentStyle enum

* Use SettingsStore for querying the comment style in SecretDetailView

Fixes: https://github.com/maxgoedjen/secretive/pull/536#discussion_r1509655340

* Revert "Use keychain instead of UserDefaults in JustUpdatedChecker.swift"

This reverts commit ae8a21a1bf7f9e2d04fcb83c4543995db0111325.

* Remove copyright info

* Use "enum Constants" in SettingsStore

* WIP

* Cleanup

* Cleanup

* Cleanup strings

* WIP

* Cleanup

* Cleanup

* Cleanup

* Cleanup

* Cleanup

---------

Co-authored-by: Paul Heidekrüger <paul.heidekrueger@tum.de>

Sources/Secretive/Views/Secrets/SettingsView.swift

@@ -0,0 +1,14 @@
+import SwiftUI
+import SettingsKit
+
+struct SettingsView: View {
+
+    @Environment(\.settingsStore) var settingsStore
+
+    var body: some View {
+        Form {
+        }
+        .padding()
+        .frame(minWidth: 480, minHeight: 320)
+    }
+}