[Rust ]Add async file stream support for reqwest client

[andershausding]

This PR adds the missing capability for single file inputstreams in the request body, for example used by the /libpod/volumes/{name}/import API from Podman. Ive added a sample and a minimal yaml below for an api using this feature.

swagger: "2.0"
info:
  title: File Streaming Test API
  version: 1.0.0

paths:
    /upload:
      post:
        consumes:
            - application/octet-stream
        description: Upload a file from the local filesystem
        operationId: uploadFile
        parameters:
          - description: A test file
            in: body
            name: inputStream
            schema:
              format: binary
              type: string
        responses:
          '200':
            description: Success

@frol @farcaller @richardwhiuk @paladinzh @jacob-pro @dsteeley @wing328

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[wing328]

thanks for the pr

tested locally to confirm the issue and the fix

$ cargo build
    Updating crates.io index
     Locking 5 packages to latest compatible versions
      Adding futures-io v0.3.31
      Adding futures-macro v0.3.31
      Adding futures-sink v0.3.31
      Adding tokio-util v0.7.16
      Adding wasm-streams v0.4.2
  Downloaded futures-io v0.3.31
  Downloaded futures-sink v0.3.31
  Downloaded futures-macro v0.3.31
  Downloaded slab v0.4.11
  Downloaded tokio-util v0.7.16
  Downloaded 5 crates (170.6KiB) in 0.51s
   Compiling tokio v1.47.1
   Compiling futures-sink v0.3.31
   Compiling hyper v1.7.0
   Compiling tower v0.5.2
   Compiling tokio-util v0.7.16
   Compiling tower-http v0.6.6
   Compiling hyper-util v0.1.16
   Compiling reqwest v0.12.23
   Compiling openapi v1.0.0 (C:\Users\wing3\AppData\Local\Temp\rustasync)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 9.12s

[wing328]

PR merged

will add a test or 2 to cover this issue moving forward in another PR

[JMLX42]

@andershausding The new supportAsync option:

• when turned on (default), it will add tokio as a dependency with features incompatible with WASM
• when turned off, it will enable the blocking feature of reqwest, which does not build for WASM

error: Only features sync,macros,io-util,rt,time are supported on wasm.
   --> /home/jmlx/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.47.1/src/lib.rs:475:1
    |
475 | compile_error!("Only features sync,macros,io-util,rt,time are supported on wasm.");
    |

So IMHO, essentially, the WASM build is broken on 7.15.