Add roqet_mode for 4 main program modes
Use mode to wrap stdin/file/uri reading for query uri mode
(rasqal_cmdline_read_uri_file_stdin_contents): Added and used
mode switch around quiet block
Use mode to wrap info and execution code
code style - declare at start of block
Use rasqal_query_results_formats_check to check valid result format
Use rasqal_query_results_formats_check to check -r/-R arguments
help message improvements
help words