Add option to OPAL Client for specifying HTTPX client timeout

[ben-kiplot]

Is your feature request related to a problem? Please describe.
OPAL Client does not support specifying a HTTP timeout when using the HTTPX client (OPAL_HTTP_FETCHER_PROVIDER_CLIENT=httpx) - the default of 5 seconds is always used.

Describe the solution you'd like
The HTTPX client timeout can be specified via environment variable

Describe alternatives you've considered
N/A

Additional context
The HTTPX client supports specifying a timeout when creating the AsyncClient which could be used here: https://github.com/permitio/opal/blob/master/packages/opal-common/opal_common/fetcher/providers/http_fetch_provider.py#L76

https://www.python-httpx.org/advanced/timeouts/

[omer9564]

Hey @ben-kiplot ,
Thanks for opening the issue, we'll open an internal ticket for that.
Of course, we'd be happy to accept a contribution if you'd like to 🤩 ( if this is urgent for you I'd suggest contributing as I currently can't guarantee any timeline on our side, I can also share contributing guidelines if you want to )