Allow trimming file paths of non native files

[brancz]

Is your feature request related to a problem? Please describe.

Interpreted languages like ruby, python, or javascript (before being JITed but same thing holds for JITed functions), it's hard to associate source code with version control for example because we can't reliably trim the working directory of the process after the fact.

Describe the solution you'd like

For any file that we put into the function metadata for interpreted and JITed functions, we trim a configurable path set via an environment variable on the process: PARCA_TRIM_FILE_PREFIX

This should be on by default but possible to turn this behavior off.

Describe alternatives you've considered

Initially proposed to trim the current working directory of the process, but customer feedback said that they have a single container that contains a monorepo, which would not work in that scenario.

Additional context

This is part of a larger chain of features to allow integrating VCS. This feature specifically is about having the right file path, when a VCS link is configured.