Advanced field converter

[Nicklas Nordborg]

The current field converter used by the BFS exporter/external program executor uses names to find a matching formula, extra value or an existing 'static' property. While this works well in many cases there are some 'problems':

• When moving a configuration from one server to another, it is not possible to include formulas, extra value definitions, etc. This must be added manually by the person that is installing the plug-ins.
• The lookup order is hardcoded. Depending on what already exists on the server, formulas/extra values may hide other properties and create unexpected results. For example, if a formula with the name 'Name' already exists, this formula would be used instead of the static property 'Name'.

The advanced field converter should provide:

• A possibility to directly in the configuration specify if a formula, a static property, extra value, etc. is wanted.
• Define formulas as part of the configuration

The goal is that a plug-in configuration that uses the advanced field converter should not need any additional manual work when transferred to another server.

[Nicklas Nordborg]

(In [5381]) Fixes #1480: Advanced field converter