Avoid running legacy liquibase changesets

It doesn't make sense to run changesets for legacy versions of OpenMRS that are unsupported now for a long time. The changesets unnecessarily slow down the initial setup.

Goal

Refactor our liquibase files so that liquibase-schema-only.xml and liquibase-core-data.xml files are versioned. At a minimum, we would like versions of these files for each major version. Ideally, we would be able to introduce these for each minor version as well, so new installs can start with a snapshot of the most recent version and only need to apply changesets for maintenance releases.

Tasks

Once TRUNK-3638 has been completed and merged, refactor the liquibase schema and core data files so they can be versioned. Consider organizing these in one or more folder(s). This will also require refactoring the startup code to start with the most recent snapshot for new installs and, for upgrades, detect the current version and only run changesets released with or after that version.

An important part of completing this ticket is ensuring that the versioning can be maintained for future versions of the platform. This means that the process for creating/updating new versions of liquibase snapshots should be documented (included in the release process documentation). Ideally, this would include creating scripts or tools to automate or semi-automate generation of the liquibase schema and core data files.