Removing all declarations and uses of annotations from the standard library

[jurgenvinju]

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• We've tested and released Rascal versions which simulate the behavior of annotation declarations and uses via the keyword field feature.
• This works well. The standard library being the biggest user of this feature (like ParseTree.rsc)
• We can now start removing all the declarations and uses of annotation syntax and replacing it by keyword field syntax with the same semantics
• There is already a refactoring script which can do this automatically (lang::rascal::refactoring::upgrade) on one of the annotation branches. This could be revived.
• After this refactoring the standard library will be rid of all the deprecation warnings by the type-checker and be a better model of how to write typical Rascal code again.