Imperative bindings for out of process languages (PowerShell, JavaScript, Python, Java)

#### What problem would the feature you're requesting solve? Please describe.
I started using Azure Functions with v2 and PowerShell as the language. Since PowerShell is so flexible, I thought imperative bindings would be logical to be used in our project over declarative bindings. Luckily there is a lot of flexibility in the function.json so I'm not blocked but still there is somewhat of a disconnect between the bindings and the PowerShell process.

#### Describe the solution you'd like
I'd like imperative bindings to be available in out of process languages (for me PowerShell)

#### Describe alternatives you've considered
Right now I'm using json body in requests to define which queue a message should be send to. This puts backend logic on the front-end which is what we would like to avoid.

#### Additional context
This issue is a follow up on [an issue](https://github.com/Azure/azure-functions-powershell-worker/issues/184) addressed at the PowerShell worker.

Start with the linked PowerShell worker issue 184 and inspect how function.json currently represents bindings for PowerShell. Compare the requested imperative-binding model across PowerShell, JavaScript, Python, and Java; done means the host and out-of-process workers support imperative bindings without requiring request JSON to choose the queue.

Written by the indexing model from the issue text.