Add ability to specify scanned input files as a list

[tinder-maxwellelliott]

Hello,

We currently use Mockolo to generate mocks in our project and it supports a flag -srcs to specify a list of files to scan. What are the blockers for enabling such a use case in Needle?

For background we are using Bazel to build our project and we receive dynamic paths from our generator scripts. This means that you cannot use absolute paths and must use helpers to format source lists into the appropriate paths. Ideally we would just give these dynamic paths as a list to Needle and it would "Just Work"

[tinder-maxwellelliott]

Looking at the code this is supported but just not documented, closing