[🐛 Bug]: Grid File download capability should be w3c compliant

[titusfortner]

What happened?

I'm sorry I didn't weigh in on #11277 before it was merged. I'm thinking of this specifically for how to get this properly consumed by the bindings as per #11443

2 things to bring the grid code more in line with other endpoints.

1. Use POST if there is info to send to an endpoint instead of query string
2. Return payload needs to be nested inside a value key.

Current implementation of file endpoint is:

POST /session/:sessionId:/se/file
file: <zippedFile>

To minimize confusion, I think the new feature should use files instead of file:

POST /session/:sessionId:/se/files
{fileName: <filename>}

and for #11458

GET /session/:sessionId:/se/files

How can we reproduce the issue?

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Relevant log output

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Operating System

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Selenium version

trunk

What are the browser(s) and version(s) where you see this issue?

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What are the browser driver(s) and version(s) where you see this issue?

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Are you using Selenium Grid?

trunk