Deprecation warning when parsing `input` folder.

[GlassAndOneHalf]

The following warning is produced when running fuzzyc2cpg on the project input folder:

Using deprecated CPG format with METHOD_INST nodes.

Update the CPG generator to use the latest CPG format.

[fabsx00]

@ml86 can you explain to @GlassAndOneHalf what this warning is about? We might want to port the frontend to the updated spec.

[ml86]

Here is the explanation: https://github.com/ShiftLeftSecurity/codescience/issues/2805#issue-492837543