[postgresql] Do not specify properties: {} in spec

This forces the properties to {} regardless
of the properties being passed in.
finish rename of postgresql_node_ng to postgresql_node
Move mysql and postgresql services into src

Rename src/ng/mysql to src/mysql_service
Rename src/ng/postgresql to src/postgresql_service
Move integration-test-support into the mysql_service folder
Update packages to look for files in their new locations

[#52259065]
Add the mysql_gateway and mysql_node_ng jobs

[#52259065]
Rename the mysql_node_ng job to mysql_node

[#52259065]
Scope node-specific config under job name in manifest

Move mysql_node config under properties.mysql_node in the manifest
Move mysql_node_external config under properties.mysql_node_external in the manifest

Also remove "free" as the default plan for these two jobs

[#52259065, #52428907]
Merge branch 'postgresql_ng_fixes' of github.com:drnic/cf-services-release into drnic-postgresql_ng_fixes

Conflicts:
jobs/postgresql_node/templates/postgresql_backup.cron.erb
jobs/postgresql_node/templates/postgresql_node_ctl
jobs/postgresql_node/templates/postgresql_worker_ctl
Fix a syntax error
Require that service_plans be provided for postgresql

[#52428907]
Namespace the plan name for postgresql_node job

[#52259065]
Remove last file in src/services