Plugins can now build apps (#4608)

* Plugins can now build apps

* fix tests

* fixup

* pluginize existing apps

* Test fixes part 1

* Test fixes part 2

* Fix Crowdfund namespace

* Syntax

* More namespace fixes

* Markup

* Test fix

* upstream fixes

* Add plugin icon

* Fix nullable build warnings

* allow pre popualting app creation

* Fixes after merge

* Make link methods async

* Use AppData as parameter for ConfigureLink

* GetApps by AppType

* Use ConfigureLink on dashboard

* Rename method

* Add properties to indicate stats support

* Property updates

* Test fixes

* Clean up imports

* Fixes after merge

---------

Co-authored-by: Dennis Reimann <mail@dennisreimann.de>

BTCPayServer/Components/MainNav/MainNav.cs

@@ -74,7 +74,7 @@ namespace BTCPayServer.Components.MainNav
                     Id = a.Id,
                     IsOwner = a.IsOwner,
                     AppName = a.AppName,
-                    AppType = Enum.Parse<AppType>(a.AppType)
+                    AppType = a.AppType
                 }).ToList();
 
                 if (PoliciesSettings.Experimental)