Allow using -? as a shorthand for -h

Given that it's quite a common switch and extremely unlikely to be already in use for something else, we can just consider it to be the same as having entered `-h` as an arg.

This adds the `?` as a valid option character name.

Fixes #1547

test/Spectre.Console.Cli.Tests/Expectations/Help/Root_Command.QuestionMark.verified.txt

@@ -0,0 +1,17 @@
+DESCRIPTION:
+The horse command.
+
+USAGE:
+    myapp horse [LEGS] [OPTIONS]
+
+ARGUMENTS:
+    [LEGS]    The number of legs
+
+OPTIONS:
+                           DEFAULT
+    -h, --help                         Prints help information
+    -a, --alive                        Indicates whether or not the animal is alive
+    -n, --name <VALUE>
+    -d, --day <MON|TUE>
+        --file             food.txt
+        --directory