Liquibase.xml files should be searched from all module jar files

When loading module liquibase.xml files, only the omod and main jar files are searched as per this line, this line, and this line. This leads into a problem where liquibase.xml files in conditionally loaded jar files are not found. I discovered this while working on TRUNK-5338 where i move the liquibase.xml file from omod/src/main/resources/liquibase.xml → api-pre2.2/src/main/resources/liquibase.xml in order for the module to create the conditions table only when running on openmrs platform versions before 2.2 as per this commit: https://github.com/openmrs/openmrs-module-emrapi/commit/27e37f3e9344954a2aa1959657d30489557ec9c4
This was a result of platform 2.2 introducing a conditions table which conflicts with the one already found in the emrapi module.

The same bug goes for the sqldiff.xml file but i did not get bothered fixing it because it is deprecated in favor of liquibase.xml.