HPCC-10736 Regression suite should allow wildcards

Add code to resolve wildcard in ECL file name to execute query.
Execute resolved ECL files one by one.
Update built in help and README.rst to reflect changes

Signed-off-by: Attila Vamos <attila.vamos@gmail.com>
Merge pull request #5313 from AttilaVamos/HPCC-10736-improvement

HPCC-10736 Regression suite should allow wildcards

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>