Make -v|--version opt-in

We added an automatic version option in 0.49. We did this with good
intentions, but forgot that people might already use --version
as an option for a root command.

This commit makes -v|--version completely opt-in.

test/Spectre.Console.Cli.Tests/Expectations/Help/ArgumentOrder.Output.verified.txt

@@ -1,4 +1,4 @@
-USAGE:
+USAGE:
     myapp <FOO> <BAR> <BAZ> <CORGI> [QUX] [OPTIONS]
 
 ARGUMENTS:
@@ -9,5 +9,4 @@ ARGUMENTS:
     [QUX]
 
 OPTIONS:
-    -h, --help       Prints help information
-    -v, --version    Prints version information
+    -h, --help    Prints help information