consolekeyinfo converter work + tests

- tweaked parameters on set-psreadlinehandler

- added ConsoleKeyInfoConverterAttribute, handles:

1. well known names from consolekey enum (escape, home, leftarrow etc.)
2. well known names with modifiers "shift+alt+ctrl+delete"
3. character literals such as "a" and "]"
4. character literals with an implied shift state like "}"
5. character literals with modifers: "shift+]"  "alt+ctrl+f1"