Strip off the srcPath when generating output - feature request

## Currently

When specifying a srcPath, the path elements become part of the output generated.

For example if you had a large project and you wanted to run Mitosis at the project route and look into `a/b/c/d/somewhere` as input, the output will end up deeply nested with `a/b/c/d/somewhere` in its path.

## Feature request

Strip off the srcPath when generating output, so that the src or other similar directories don’t become part of the output path; one should be able to move the Mitosis input around the filesystem **without** affecting Mitosis output.

This change would not be noticed in small trivial projects, but is of important when integrating into a larger build tool/build system.

## Workaround

Wrapper script to `cd` and run Mitosis from wherever the input is.

(This is a very common technique when integrating a tool into a build system.)

Start by tracing how Mitosis resolves srcPath and constructs generated output paths, then inspect the CLI or build-system entry point that receives the input directory. Verify the behavior by running the tool from a project root and from a relocated input directory; done means the generated output no longer includes the srcPath's parent elements.

Written by the indexing model from the issue text.