More tolerant linking to Cocoda via URL with mapping

[nichtich]

Linking into the application with a mapping requires the parameters:

• fromScheme
• toScheme
• from
• to
• mapping

The last parameter should be enough (example link). If no concept scheme and/or no concept is selected left or right, the missing query values of fromScheme, toScheme, from, to can be guessed from the mapping.

[stefandesu]

I implemented it this way:

• For each side (from/to):
  • If no scheme was set, set scheme from mapping.
  • If scheme from mapping was set, also set concept from mapping.

In case a scheme was already set in fromScheme or toScheme, the concept will currently not be set from the mapping. We can add this later by comparing the scheme in fromScheme/toScheme from the mapping scheme and setting it only when they match.