#801 Annotation argument syntax change + name optional + @doc multiple unnamed arguments

• Best to review per commit. There are quite a few, as I made small steps. But not that much is going on.
• The changes seem big, but the changes are actually relatively small. Mostly generated code and test updates make it seem bigger.
• There are 3 changes. For each change I updated everything to be consistent again, before moving to the next one:
  • Change syntax of annotation arguments to use : instead of =, to separate an argument's name and value.
  • Allow unnamed annotation arguments, so only an Expression.
  • Change the @doc annotation to allow multiple unnamed arguments.
• For the second change, allowing unnamed annotation arguments, the following not-directly-related changes we done as well:
  • Small textual improvements to the CIF Ecore docs, related to annotations.
  • Use AName for anno argument names in the AST, to use its keyword escape handling. The type checker then does no need to handle escaping anymore.
  • Some small improvements in the CIF documentation, related to annotations.

Closes #801 (closed)