`lifeCycleData.json` should follow the recommendations

[christoph-maurer]

The following topics are recommended for the keys lifeCycleAssessment and circularity based on Madaster as well as for the key compliance based on EPEA:

• Fix typos like "AddedConnectionConnection".
• Use lower camel case consistently like the other schemas.
• Exchange acronyms like "sm" and "rsf" by "secondaryMaterial" and "renewableSecondaryFuels".
• Exchange abbreviations like "n.v." by a self-explaining string like "noValueAvailable". Using spaces and . makes it difficult to parse those enum members in languages like C# or Java because the enumerations there do not allow these characters. Rather use an expressive lower camel-case string with a-Z0-9 characters and add the description of those in a more readable form in the description of the enum.
• Check if flags like "OnlyConstructiveWoodProtection": { "type": "boolean" can be modeled more elegantly and if they are any interrelations. A more elegant way may be an enumeration for mutually exclusive elements of a similar kind.

This should make it easier for all software developers who work with the product data network and the lifeCycleData schema in the future.

[christoph-maurer]

@aklefenz I was wrong about the structure with the properties "data" and "serverSpecific". We hope that we can avoid a key "serverSpecific". Therefore, I delete this bullet point from the list in the first comment.