Running several adapters on the same input

[arnaud-secondlayer]

Feature request

I'd like to be able to run several adapters on the same input.
For example, being able to call the python client function with several adapters instead of a single one and retrieve the answers of all the adapters at the same time.

Motivation

There are many cases where we want to run several distinct adapters on a user input. Being able to list all the adapters in a single function call would save on sending the user input several times, and we may be able to share some computing across adapters because we know the input is the same.

Your contribution

With some guidance, I should be able to create a PR.

[veezbo]

I'd like to +1 this use case, which is particularly useful when each adapter is actually a classifier and we want each to run over the same input.