Read only inputs container for supervisor tasks

[jagunter]

Support for a read-only input container for supervisor tasks that is guaranteed to be fully downloaded before fuzzing begins. The existing inputs container cannot suffice for this because even if the wait_for_files flag is provided, it only guarantees that at least one file is downloaded. We have a scenario where we need to ensure that a set of files are fully downloaded before fuzzing begins.

AB#160798

[jagunter]

We would also need to be able to identify this container through the command replacements to pass to our fuzzer. Currently our supervisor task uses {input_corpus} to refer to the inputs container.

[stishkin]

@jagunter changing wait_for_files to wait for all files to be downloaded. Will that work for you ?

[jagunter]

Yep that would work.