Sort classpath for plugins from POMs
Remove redundant classes directory for plugins

The target/classes directory is already included in the resolved classpath
returned by the artifact resolver.
Use canonical file names for plugin classpath
Add debug logging for plugin installation
Split Session and ConnectorSession

Only use ConnectorSession in ConnectorMetadata, Functions and Types
Remove unused properties from ConnectorSession

Remove source, catalog, remoteUserAddress and userAgent from ConnectorSession
Remove ConnectorSession helper constructor
Add shared testing Session instance
Add Session.builder()
Add utility to create Session from http request