implemented actually using Host.publicKey and Host.privateKey to store pubkeys and privkeys

- this gives u icloud synced pub/privkeys
 - per host!!
made it load the key's string representation (if present) into the textboxes to tell the user that the key is there
made the privkey box a securefield to show .... instead of the key

added a handler.go() to handler disconnecting if connected and choosing password/pubkey auth
- really cleaned up the view code
added getPubkey(_: SecKey) to keychainmanager
added SSHErrors - commfail, connectionFail, backenderror
added AuthError - rejectedCreds, notconnected
added KeyError - importpub/privError, pub/priv rejected
made most functions throw in sshhandler
fix memoryLayoutsize(ofvalue to buffer.count in testexec
[weak self] in the async loop to prevent memory leaks i guess
added loccritical for easy red logging

ShhShell/Views/Terminal/ShellView.swift

@@ -18,17 +18,12 @@ struct ShellView: View {
 			.toolbar {
 				ToolbarItem {
 					Button() {
-						if handler.connected {
-							handler.disconnect()
-						} else {
-							handler.connect()
-						}
+						handler.go()
 					} label: {
-						if handler.connected {
-							Label("Disconnect", systemImage: "xmark.square.fill")
-						} else {
-							Label("Connect", image: "power")
-						}
+						Label(
+							handler.connected ? "Disconnect" : "Connect",
+							systemImage: handler.connected ? "xmark.app.fill" : "power"
+						)
 					}
 				}
 			}