examples/searchcommands_app update + improved unit tetsts + bug fixes

Feature changes

+ SimulateCommand
Includes seed option that enables testing in a predictable way

Improved unit tests

+ Updated test_*_in_isoltion
+ Stubbed test_*_on_server

Bug fixes

+ Error message that "Static configuration is unsupported" is semantically incorrect
Fix is in search_command.py at or about lines 188-190

+ SearchCommandParser.unquote does not implement Splunk quote rules
Fix is at or about lines 310-335 in search_command_internals.py. Fix is not ready for production, but does unblock Shakeel

+ Validators do not format the data types they represent.
Fix is in flight. See validators.py