[kotlin2cpg] Improve fullnames.

[ml86]

Improve and cleanup the fullname calculation for methods and callsites.
The most noteable changes here are:

1. The lambda function naming schema changed from
   package.<fileName>.<lambda>counter:signature to
   package.scope.<lambda>counter:signature.
   This give a better indication which lambda function is represented
   also gets rid of exception of using the filename in the method
   fullnames.
2. Fixed lambda function signatures.
3. The fullname schema of extension methods changed from
   extendedClassFullName.extensionMethodName:signatureWithoutThisParameter
   to
   package.extensionMethodName:signatureWithThisParameter
   The fact that the this parameter is part of the signature is an
   exception in our java fullnames but necessary in order to distinguish
   otherwise identical extension methods.
4. We avoid the recalculation of the binding context with every file
   processed. This is now done once at the begining.
5. Calls to ::class are now represented as calls to
   <operator>.class.
6. Calculate proper BINDING nodes for lambda and anonymous functions.
7. Calculate proper base class for type decls created for lambda and anonymous functions.
8. Fully removed old TypeRenderer class. All full names now go via new rendering.
9. --keep-type-arguments has no effect anymore. This feature was only implemented partially and
   we might bring it back later.

[maltek]

looks much better than before :)