[Test Proxy] Support AsyncioRequestsTransport

[laiapat]

Description

We currently only patch AioHttpTransport, the most common async transport in the SDK. App Configuration uses AsyncioRequestsTransport as its async transport though -- whether or not it should hard code this is being discussed separately, but in any case our test proxy infrastructure should support any transport that clients choose to use.

This adds support for AsyncioRequestsTransport by patching its send method during recorded tests, just as we currently do for AioHttpTransport.

All SDK Contribution checklist:

• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

General Guidelines and Best Practices

• Title of the pull request is clear and informative.
• There are a small number of commits, each of which have an informative message. This means that previously merged commits do not appear in the history of the PR. For more information on cleaning up the commits in your PR, see this page.

Testing Guidelines

• Pull request includes test coverage for the included changes.
  • Tested using App Configuration tests.

[laiapat]

Just talked to Laurent about this. His opinion is that the test proxy should be allowed to depend on a single async transport -- in this case, AioHttpTransport. The problem is that App Config currently has some tests fail if AioHttpTransport is used with clients.

The solution should be to fix App Config's dependence on AsyncioRequestsTransport so that tests can use azure-core's default async transport (AioHttpTransport). That's going to take some investigation since there are some tests failing with AioHttpTransport today, so I'll leave this PR up in case we need test proxy support to get App Config migrated. (Or if we change our minds and decide to support more than just AioHttpTransport)

[laiapat]

Merging, per #26140 (comment). We can drop this support later on once App Config has proper support for AioHttpTransport, but for now the lack of AsyncioRequestsTransport in the test proxy is blocking their migration