Moved analyzer tests to its own project

Also moves tests to `./test` which makes it possible
for all test projects to share the same .editorconfig
files and similar.

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

@@ -0,0 +1,11 @@
+USAGE:
+    myapp [OPTIONS] <COMMAND>
+
+OPTIONS:
+    -h, --help       Prints help information
+    -v, --version    Prints version information
+
+COMMANDS:
+    dog <AGE>           The dog command
+    horse               The horse command
+    giraffe <LENGTH>    The giraffe command