Scan properties files from classpath and fetch the mapping automatically

[nithy1603]

This change scans for properties files in the classpath with pattern *-typemapping.properties and automatically fetches the mapping from them. This will remove the need to know the file paths and ensure that the mapping files are fetched even if they are not present in the maven plugin configuration.

Please note that if the typeMappingPropertiesFiles are specified in the configuration, then this scanning is not done. This allows for exclusion of typemapping properties if they are not required.