Wrong Error Type for read timeouts

[dibahlfi]

for read timeouts azure-core returns a ServiceResponseError which is not correct. it should be a timeout error. Please verify this behavior for both aio and requests libraries.

[github-actions]

@kashifkhan @xiangyan99

[annatisch]

It looks like aiohttp is raising the correct errors here:
https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/core/azure-core/azure/core/pipeline/transport/_aiohttp.py#L388-L391

However the requests transport is raising a ServiceResponseError instead of the correct ServiceResponseTimeoutError:
https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/core/azure-core/azure/core/pipeline/transport/_requests_basic.py#L392-L393
This should be an easy fix.

The requests transport also appears to have no support for ServiceRequestTimeoutError - so that should be further explored.
That could maybe be done as a subsequent fix if we want to prioritize getting the first fix in.